diff --git a/DifferentiationInterface/CHANGELOG.md b/DifferentiationInterface/CHANGELOG.md
index a792b1039..a3da3a10c 100644
--- a/DifferentiationInterface/CHANGELOG.md
+++ b/DifferentiationInterface/CHANGELOG.md
@@ -7,8 +7,11 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [0.7.0]
+
 ### Changed
 
+- Preparation is now strict by default ([#799])
 - New Arxiv preprint for citation ([#795])
 
 ## [0.6.54] - 2025-05-11
@@ -24,10 +27,12 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - Allocate Enzyme shadow memory during preparation ([#782])
 
-[unreleased]: https://github.com/JuliaDiff/DifferentiationInterface.jl/compare/DifferentiationInterface-v0.6.54...main
+[unreleased]: https://github.com/JuliaDiff/DifferentiationInterface.jl/compare/DifferentiationInterface-v0.7.0...main
+[0.7.0]: https://github.com/JuliaDiff/DifferentiationInterface.jl/compare/DifferentiationInterface-v0.6.54...DifferentiationInterface-v0.7.0
 [0.6.54]: https://github.com/JuliaDiff/DifferentiationInterface.jl/compare/DifferentiationInterface-v0.6.53...DifferentiationInterface-v0.6.54
 [0.6.53]: https://github.com/JuliaDiff/DifferentiationInterface.jl/compare/DifferentiationInterface-v0.6.52...DifferentiationInterface-v0.6.53
 
+[#799]: https://github.com/JuliaDiff/DifferentiationInterface.jl/pull/799
 [#795]: https://github.com/JuliaDiff/DifferentiationInterface.jl/pull/795
 [#790]: https://github.com/JuliaDiff/DifferentiationInterface.jl/pull/790
 [#788]: https://github.com/JuliaDiff/DifferentiationInterface.jl/pull/788
diff --git a/DifferentiationInterface/Project.toml b/DifferentiationInterface/Project.toml
index 8d39ac708..486b91a5b 100644
--- a/DifferentiationInterface/Project.toml
+++ b/DifferentiationInterface/Project.toml
@@ -1,7 +1,7 @@
 name = "DifferentiationInterface"
 uuid = "a0c0ee7d-e4b9-4e03-894e-1c5f64a51d63"
 authors = ["Guillaume Dalle", "Adrian Hill"]
-version = "0.6.54"
+version = "0.7.0"
 
 [deps]
 ADTypes = "47edcb42-4c32-4615-8424-f2b9edc5f35b"
diff --git a/DifferentiationInterface/src/docstrings.jl b/DifferentiationInterface/src/docstrings.jl
index e14ccfb52..6e22c2f1c 100644
--- a/DifferentiationInterface/src/docstrings.jl
+++ b/DifferentiationInterface/src/docstrings.jl
@@ -26,7 +26,8 @@ function docstring_prepare(operator; samepoint=false, inplace=false)
         Otherwise, preparation becomes invalid and you need to run it again.
         In some settings, invalid preparations may still give correct results (e.g. for backends that require no preparation), but this is not a semantic guarantee and should not be relied upon.
 
-    When `strict=Val(true)`, type checking is enforced between preparation and execution (but size checking is left to the user).
+    When `strict=Val(true)` (the default), type checking is enforced between preparation and execution (but size checking is left to the user).
+    While your code may work for different types by setting `strict=Val(false)`, this is not guaranteed by the API and can break without warning.
     """
 end
 
diff --git a/DifferentiationInterface/src/first_order/derivative.jl b/DifferentiationInterface/src/first_order/derivative.jl
index 1784247d8..4883f1c82 100644
--- a/DifferentiationInterface/src/first_order/derivative.jl
+++ b/DifferentiationInterface/src/first_order/derivative.jl
@@ -1,24 +1,19 @@
 ## Docstrings
 
 """
-    prepare_derivative(f,     backend, x, [contexts...]; strict=Val(false)) -> prep
-    prepare_derivative(f!, y, backend, x, [contexts...]; strict=Val(false)) -> prep
+    prepare_derivative(f,     backend, x, [contexts...]; strict=Val(true)) -> prep
+    prepare_derivative(f!, y, backend, x, [contexts...]; strict=Val(true)) -> prep
 
 $(docstring_prepare("derivative"; inplace=true))
 """
 function prepare_derivative(
-    f::F, backend::AbstractADType, x, contexts::Vararg{Context,C}; strict::Val=Val(false)
+    f::F, backend::AbstractADType, x, contexts::Vararg{Context,C}; strict::Val=Val(true)
 ) where {F,C}
     return prepare_derivative_nokwarg(strict, f, backend, x, contexts...)
 end
 
 function prepare_derivative(
-    f!::F,
-    y,
-    backend::AbstractADType,
-    x,
-    contexts::Vararg{Context,C};
-    strict::Val=Val(false),
+    f!::F, y, backend::AbstractADType, x, contexts::Vararg{Context,C}; strict::Val=Val(true)
 ) where {F,C}
     return prepare_derivative_nokwarg(strict, f!, y, backend, x, contexts...)
 end
@@ -42,8 +37,7 @@ function prepare!_derivative(
     old_prep::DerivativePrep,
     backend::AbstractADType,
     x,
-    contexts::Vararg{Context,C};
-    strict::Val=Val(false),
+    contexts::Vararg{Context,C},
 ) where {F,C}
     check_prep(f!, y, old_prep, backend, x, contexts...)
     return prepare_derivative_nokwarg(is_strict(old_prep), f!, y, backend, x, contexts...)
diff --git a/DifferentiationInterface/src/first_order/gradient.jl b/DifferentiationInterface/src/first_order/gradient.jl
index 426fb205b..448adba16 100644
--- a/DifferentiationInterface/src/first_order/gradient.jl
+++ b/DifferentiationInterface/src/first_order/gradient.jl
@@ -1,12 +1,12 @@
 ## Docstrings
 
 """
-    prepare_gradient(f, backend, x, [contexts...]; strict=Val(false)) -> prep
+    prepare_gradient(f, backend, x, [contexts...]; strict=Val(true)) -> prep
 
 $(docstring_prepare("gradient"))
 """
 function prepare_gradient(
-    f::F, backend::AbstractADType, x, contexts::Vararg{Context,C}; strict::Val=Val(false)
+    f::F, backend::AbstractADType, x, contexts::Vararg{Context,C}; strict::Val=Val(true)
 ) where {F,C}
     return prepare_gradient_nokwarg(strict, f, backend, x, contexts...)
 end
diff --git a/DifferentiationInterface/src/first_order/jacobian.jl b/DifferentiationInterface/src/first_order/jacobian.jl
index 997a4dc75..5e6a07280 100644
--- a/DifferentiationInterface/src/first_order/jacobian.jl
+++ b/DifferentiationInterface/src/first_order/jacobian.jl
@@ -1,24 +1,19 @@
 ## Docstrings
 
 """
-    prepare_jacobian(f,     backend, x, [contexts...]; strict=Val(false)) -> prep
-    prepare_jacobian(f!, y, backend, x, [contexts...]; strict=Val(false)) -> prep
+    prepare_jacobian(f,     backend, x, [contexts...]; strict=Val(true)) -> prep
+    prepare_jacobian(f!, y, backend, x, [contexts...]; strict=Val(true)) -> prep
 
 $(docstring_prepare("jacobian"; inplace=true))
 """
 function prepare_jacobian(
-    f::F, backend::AbstractADType, x, contexts::Vararg{Context,C}; strict::Val=Val(false)
+    f::F, backend::AbstractADType, x, contexts::Vararg{Context,C}; strict::Val=Val(true)
 ) where {F,C}
     return prepare_jacobian_nokwarg(strict, f, backend, x, contexts...)
 end
 
 function prepare_jacobian(
-    f!::F,
-    y,
-    backend::AbstractADType,
-    x,
-    contexts::Vararg{Context,C};
-    strict::Val=Val(false),
+    f!::F, y, backend::AbstractADType, x, contexts::Vararg{Context,C}; strict::Val=Val(true)
 ) where {F,C}
     return prepare_jacobian_nokwarg(strict, f!, y, backend, x, contexts...)
 end
@@ -43,7 +38,6 @@ function prepare!_jacobian(
     backend::AbstractADType,
     x,
     contexts::Vararg{Context,C};
-    strict::Val=Val(false),
 ) where {F,C}
     check_prep(f!, y, old_prep, backend, x, contexts...)
     return prepare_jacobian_nokwarg(is_strict(old_prep), f!, y, backend, x, contexts...)
diff --git a/DifferentiationInterface/src/first_order/pullback.jl b/DifferentiationInterface/src/first_order/pullback.jl
index 2ac1265c0..9d207d9e8 100644
--- a/DifferentiationInterface/src/first_order/pullback.jl
+++ b/DifferentiationInterface/src/first_order/pullback.jl
@@ -1,8 +1,8 @@
 ## Docstrings
 
 """
-    prepare_pullback(f,     backend, x, ty, [contexts...]; strict=Val(false)) -> prep
-    prepare_pullback(f!, y, backend, x, ty, [contexts...]; strict=Val(false)) -> prep
+    prepare_pullback(f,     backend, x, ty, [contexts...]; strict=Val(true)) -> prep
+    prepare_pullback(f!, y, backend, x, ty, [contexts...]; strict=Val(true)) -> prep
 
 $(docstring_prepare("pullback"; inplace=true))
 """
@@ -12,7 +12,7 @@ function prepare_pullback(
     x,
     ty::NTuple,
     contexts::Vararg{Context,C};
-    strict::Val=Val(false),
+    strict::Val=Val(true),
 ) where {F,C}
     return prepare_pullback_nokwarg(strict, f, backend, x, ty, contexts...)
 end
@@ -24,7 +24,7 @@ function prepare_pullback(
     x,
     ty::NTuple,
     contexts::Vararg{Context,C};
-    strict::Val=Val(false),
+    strict::Val=Val(true),
 ) where {F,C}
     return prepare_pullback_nokwarg(strict, f!, y, backend, x, ty, contexts...)
 end
@@ -61,8 +61,8 @@ function prepare!_pullback(
 end
 
 """
-    prepare_pullback_same_point(f,     backend, x, ty, [contexts...]; strict=Val(false)) -> prep_same
-    prepare_pullback_same_point(f!, y, backend, x, ty, [contexts...]; strict=Val(false)) -> prep_same
+    prepare_pullback_same_point(f,     backend, x, ty, [contexts...]; strict=Val(true)) -> prep_same
+    prepare_pullback_same_point(f!, y, backend, x, ty, [contexts...]; strict=Val(true)) -> prep_same
 
 $(docstring_prepare("pullback"; samepoint=true, inplace=true))
 """
@@ -72,7 +72,7 @@ function prepare_pullback_same_point(
     x,
     ty::NTuple,
     contexts::Vararg{Context,C};
-    strict::Val=Val(false),
+    strict::Val=Val(true),
 ) where {F,C}
     return prepare_pullback_same_point_nokwarg(strict, f, backend, x, ty, contexts...)
 end
@@ -84,7 +84,7 @@ function prepare_pullback_same_point(
     x,
     ty::NTuple,
     contexts::Vararg{Context,C};
-    strict::Val=Val(false),
+    strict::Val=Val(true),
 ) where {F,C}
     return prepare_pullback_same_point_nokwarg(strict, f!, y, backend, x, ty, contexts...)
 end
diff --git a/DifferentiationInterface/src/first_order/pushforward.jl b/DifferentiationInterface/src/first_order/pushforward.jl
index edba42655..11cfbf185 100644
--- a/DifferentiationInterface/src/first_order/pushforward.jl
+++ b/DifferentiationInterface/src/first_order/pushforward.jl
@@ -1,8 +1,8 @@
 ## Docstrings
 
 """
-    prepare_pushforward(f,     backend, x, tx, [contexts...]; strict=Val(false)) -> prep
-    prepare_pushforward(f!, y, backend, x, tx, [contexts...]; strict=Val(false)) -> prep
+    prepare_pushforward(f,     backend, x, tx, [contexts...]; strict=Val(true)) -> prep
+    prepare_pushforward(f!, y, backend, x, tx, [contexts...]; strict=Val(true)) -> prep
 
 $(docstring_prepare("pushforward"; inplace=true))
 """
@@ -12,7 +12,7 @@ function prepare_pushforward(
     x,
     tx::NTuple,
     contexts::Vararg{Context,C};
-    strict::Val=Val(false),
+    strict::Val=Val(true),
 ) where {F,C}
     return prepare_pushforward_nokwarg(strict, f, backend, x, tx, contexts...)
 end
@@ -24,7 +24,7 @@ function prepare_pushforward(
     x,
     tx::NTuple,
     contexts::Vararg{Context,C};
-    strict::Val=Val(false),
+    strict::Val=Val(true),
 ) where {F,C}
     return prepare_pushforward_nokwarg(strict, f!, y, backend, x, tx, contexts...)
 end
@@ -63,8 +63,8 @@ function prepare!_pushforward(
 end
 
 """
-    prepare_pushforward_same_point(f,     backend, x, tx, [contexts...]; strict=Val(false)) -> prep_same
-    prepare_pushforward_same_point(f!, y, backend, x, tx, [contexts...]; strict=Val(false)) -> prep_same
+    prepare_pushforward_same_point(f,     backend, x, tx, [contexts...]; strict=Val(true)) -> prep_same
+    prepare_pushforward_same_point(f!, y, backend, x, tx, [contexts...]; strict=Val(true)) -> prep_same
 
 $(docstring_prepare("pushforward"; samepoint=true, inplace=true))
 """
@@ -74,7 +74,7 @@ function prepare_pushforward_same_point(
     x,
     tx::NTuple,
     contexts::Vararg{Context,C};
-    strict::Val=Val(false),
+    strict::Val=Val(true),
 ) where {F,C}
     return prepare_pushforward_same_point_nokwarg(strict, f, backend, x, tx, contexts...)
 end
@@ -86,7 +86,7 @@ function prepare_pushforward_same_point(
     x,
     tx::NTuple,
     contexts::Vararg{Context,C};
-    strict::Val=Val(false),
+    strict::Val=Val(true),
 ) where {F,C}
     return prepare_pushforward_same_point_nokwarg(
         strict, f!, y, backend, x, tx, contexts...
diff --git a/DifferentiationInterface/src/second_order/hessian.jl b/DifferentiationInterface/src/second_order/hessian.jl
index 8e17cff99..ffb6ba840 100644
--- a/DifferentiationInterface/src/second_order/hessian.jl
+++ b/DifferentiationInterface/src/second_order/hessian.jl
@@ -1,12 +1,12 @@
 ## Docstrings
 
 """
-    prepare_hessian(f, backend, x, [contexts...]; strict=Val(false)) -> prep
+    prepare_hessian(f, backend, x, [contexts...]; strict=Val(true)) -> prep
 
 $(docstring_prepare("hessian"))
 """
 function prepare_hessian(
-    f::F, backend::AbstractADType, x, contexts::Vararg{Context,C}; strict::Val=Val(false)
+    f::F, backend::AbstractADType, x, contexts::Vararg{Context,C}; strict::Val=Val(true)
 ) where {F,C}
     return prepare_hessian_nokwarg(strict, f, backend, x, contexts...)
 end
diff --git a/DifferentiationInterface/src/second_order/hvp.jl b/DifferentiationInterface/src/second_order/hvp.jl
index 1c4f3292a..8a85bf1c1 100644
--- a/DifferentiationInterface/src/second_order/hvp.jl
+++ b/DifferentiationInterface/src/second_order/hvp.jl
@@ -1,7 +1,7 @@
 ## Docstrings
 
 """
-    prepare_hvp(f, backend, x, tx, [contexts...]; strict=Val(false)) -> prep
+    prepare_hvp(f, backend, x, tx, [contexts...]; strict=Val(true)) -> prep
 
 $(docstring_prepare("hvp"))
 """
@@ -11,7 +11,7 @@ function prepare_hvp(
     x,
     tx::NTuple,
     contexts::Vararg{Context,C};
-    strict::Val=Val(false),
+    strict::Val=Val(true),
 ) where {F,C}
     return prepare_hvp_nokwarg(strict, f, backend, x, tx, contexts...)
 end
@@ -34,7 +34,7 @@ function prepare!_hvp(
 end
 
 """
-    prepare_hvp_same_point(f, backend, x, tx, [contexts...]; strict=Val(false)) -> prep_same
+    prepare_hvp_same_point(f, backend, x, tx, [contexts...]; strict=Val(true)) -> prep_same
 
 $(docstring_prepare("hvp"; samepoint=true))
 """
@@ -44,7 +44,7 @@ function prepare_hvp_same_point(
     x,
     tx::NTuple,
     contexts::Vararg{Context,C};
-    strict::Val=Val(false),
+    strict::Val=Val(true),
 ) where {F,C}
     return prepare_hvp_same_point_nokwarg(strict, f, backend, x, tx, contexts...)
 end
diff --git a/DifferentiationInterface/src/second_order/second_derivative.jl b/DifferentiationInterface/src/second_order/second_derivative.jl
index 5c0903153..3d5b8c905 100644
--- a/DifferentiationInterface/src/second_order/second_derivative.jl
+++ b/DifferentiationInterface/src/second_order/second_derivative.jl
@@ -1,12 +1,12 @@
 ## Docstrings
 
 """
-    prepare_second_derivative(f, backend, x, [contexts...]; strict=Val(false)) -> prep
+    prepare_second_derivative(f, backend, x, [contexts...]; strict=Val(true)) -> prep
 
 $(docstring_prepare("second_derivative"))
 """
 function prepare_second_derivative(
-    f::F, backend::AbstractADType, x, contexts::Vararg{Context,C}; strict::Val=Val(false)
+    f::F, backend::AbstractADType, x, contexts::Vararg{Context,C}; strict::Val=Val(true)
 ) where {F,C}
     return prepare_second_derivative_nokwarg(strict, f, backend, x, contexts...)
 end
diff --git a/DifferentiationInterface/test/Core/Internals/signature.jl b/DifferentiationInterface/test/Core/Internals/signature.jl
index be2e144c1..3c326c4c7 100644
--- a/DifferentiationInterface/test/Core/Internals/signature.jl
+++ b/DifferentiationInterface/test/Core/Internals/signature.jl
@@ -11,7 +11,7 @@ y = zeros(2)
 c = 2.0
 
 @testset "Out of place, no tangents" begin
-    prep = prepare_derivative(f, backend, x, Constant(c); strict=Val(true))
+    prep = prepare_derivative(f, backend, x, Constant(c))
     prep_chill = prepare_derivative(f, backend, x, Constant(c); strict=Val(false))
 
     @test_throws MethodError derivative(nothing, prep_chill, backend, x, Constant(c))
@@ -68,7 +68,7 @@ c = 2.0
 end
 
 @testset "In place, no tangents" begin
-    prep = prepare_derivative(f!, y, backend, x; strict=Val(true))
+    prep = prepare_derivative(f!, y, backend, x)
     prep_chill = prepare_derivative(f!, y, backend, x; strict=Val(false))
 
     @test_throws MethodError derivative(nothing, y, prep_chill, backend, x, Constant(c))
@@ -86,7 +86,7 @@ end
 end
 
 @testset "Out of place, with tangents" begin
-    prep = prepare_pushforward(f, backend, x, (x,), Constant(c); strict=Val(true))
+    prep = prepare_pushforward(f, backend, x, (x,), Constant(c))
     prep_chill = prepare_pushforward(f, backend, x, (x,), Constant(c); strict=Val(false))
 
     @test_throws MethodError pushforward(nothing, prep_chill, backend, x, (x,))
@@ -104,7 +104,7 @@ end
 end
 
 @testset "In place, with tangents" begin
-    prep = prepare_pushforward(f!, y, backend, x, (x,); strict=Val(true))
+    prep = prepare_pushforward(f!, y, backend, x, (x,))
     prep_chill = prepare_pushforward(
         f!, y, backend, x, (x,), Constant(c); strict=Val(false)
     )
diff --git a/DifferentiationInterfaceTest/CHANGELOG.md b/DifferentiationInterfaceTest/CHANGELOG.md
index fb687131b..764ffd6ff 100644
--- a/DifferentiationInterfaceTest/CHANGELOG.md
+++ b/DifferentiationInterfaceTest/CHANGELOG.md
@@ -7,6 +7,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [0.10.0]
+
 ### Changed
 
 - Specify preparation arguments in DIT Scenario ([#786])
@@ -23,7 +25,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Support nested tuples of arrays as Caches ([#748])
 - Test type consistency between preparation and execution ([#745])
 
-[unreleased]: https://github.com/JuliaDiff/DifferentiationInterface.jl/compare/DifferentiationInterfaceTest-v0.9.6...main
+[unreleased]: https://github.com/JuliaDiff/DifferentiationInterface.jl/compare/DifferentiationInterfaceTest-v0.10.0...main
+[0.10.0]: https://github.com/JuliaDiff/DifferentiationInterface.jl/compare/DifferentiationInterfaceTest-v0.9.6...DifferentiationInterfaceTest-v0.10.0
 [0.9.6]: https://github.com/JuliaDiff/DifferentiationInterface.jl/compare/DifferentiationInterfaceTest-v0.9.5...DifferentiationInterfaceTest-v0.9.6
 
 [#796]: https://github.com/JuliaDiff/DifferentiationInterface.jl/pull/796
diff --git a/DifferentiationInterfaceTest/Project.toml b/DifferentiationInterfaceTest/Project.toml
index 0ff69f682..666ec721b 100644
--- a/DifferentiationInterfaceTest/Project.toml
+++ b/DifferentiationInterfaceTest/Project.toml
@@ -1,7 +1,7 @@
 name = "DifferentiationInterfaceTest"
 uuid = "a82114a7-5aa3-49a8-9643-716bb13727a3"
 authors = ["Guillaume Dalle", "Adrian Hill"]
-version = "0.10.0"
+version = "0.10.1"
 
 [deps]
 ADTypes = "47edcb42-4c32-4615-8424-f2b9edc5f35b"
@@ -44,7 +44,7 @@ AllocCheck = "0.2"
 Chairmarks = "1.2.1"
 ComponentArrays = "0.15"
 DataFrames = "1.6.1"
-DifferentiationInterface = "0.6.53"
+DifferentiationInterface = "0.7.0"
 DocStringExtensions = "0.8,0.9"
 ExplicitImports = "1.10.1"
 FiniteDiff = "2.27.0"
diff --git a/DifferentiationInterfaceTest/src/tests/correctness_eval.jl b/DifferentiationInterfaceTest/src/tests/correctness_eval.jl
index dbecdbbc7..22208bb43 100644
--- a/DifferentiationInterfaceTest/src/tests/correctness_eval.jl
+++ b/DifferentiationInterfaceTest/src/tests/correctness_eval.jl
@@ -55,17 +55,17 @@ for op in ALL_OPS
             reprepare::Bool,
         )
             (; f, x, y, res1, contexts, prep_args) = new_scen = deepcopy(scen)
-            local prepstrict
+            local prep
             preptup_cands_val, preptup_cands_noval = map(1:2) do _
                 prep = $prep_op(f, ba, prep_args.x, prep_args.contexts...)
-                prepstrict = $prep_op(
-                    f, ba, prep_args.x, prep_args.contexts...; strict=Val(true)
+                prep_nostrict = $prep_op(
+                    f, ba, prep_args.x, prep_args.contexts...; strict=Val(false)
                 )
                 if reprepare && has_size(x) && has_size(y) && (size(x) != size(prep_args.x))
                     prep = $prep_op!(f, prep, ba, x, contexts...)
-                    prepstrict = $prep_op!(f, prepstrict, ba, x, contexts...)
+                    prep_nostrict = $prep_op!(f, prep_nostrict, ba, x, contexts...)
                 end
-                [(), (prep,), (prepstrict,)]
+                [(), (prep,), (prep_nostrict,)]
             end
             for (preptup_val, preptup_noval) in zip(preptup_cands_val, preptup_cands_noval)
                 y_out1_val, res1_out1_val = $val_and_op(
@@ -92,8 +92,8 @@ for op in ALL_OPS
                     @test mynnz(res1_out2_noval) == mynnz(scen.res1)
                 end
             end
-            @test_throws PME $val_and_op(nothing, prepstrict, ba, x, contexts...)
-            @test_throws PME $op(nothing, prepstrict, ba, x, contexts...)
+            @test_throws PME $val_and_op(nothing, prep, ba, x, contexts...)
+            @test_throws PME $op(nothing, prep, ba, x, contexts...)
             scenario_intact && @test new_scen == scen
             return nothing
         end
@@ -109,17 +109,17 @@ for op in ALL_OPS
             reprepare::Bool,
         )
             (; f, x, y, res1, contexts, prep_args) = new_scen = deepcopy(scen)
-            local prepstrict
+            local prep
             preptup_cands_val, preptup_cands_noval = map(1:2) do _
                 prep = $prep_op(f, ba, prep_args.x, prep_args.contexts...)
-                prepstrict = $prep_op(
-                    f, ba, prep_args.x, prep_args.contexts...; strict=Val(true)
+                prep_nostrict = $prep_op(
+                    f, ba, prep_args.x, prep_args.contexts...; strict=Val(false)
                 )
                 if reprepare && has_size(x) && has_size(y) && (size(x) != size(prep_args.x))
                     prep = $prep_op!(f, prep, ba, x, contexts...)
-                    prepstrict = $prep_op!(f, prepstrict, ba, x, contexts...)
+                    prep_nostrict = $prep_op!(f, prep_nostrict, ba, x, contexts...)
                 end
-                [(), (prep,), (prepstrict,)]
+                [(), (prep,), (prep_nostrict,)]
             end
             for (preptup_val, preptup_noval) in zip(preptup_cands_val, preptup_cands_noval)
                 res1_in1_val = mysimilar(res1)
@@ -159,9 +159,9 @@ for op in ALL_OPS
                 end
             end
             @test_throws PME $val_and_op!(
-                nothing, mysimilar(res1), prepstrict, ba, x, contexts...
+                nothing, mysimilar(res1), prep, ba, x, contexts...
             )
-            @test_throws PME $op!(nothing, mysimilar(res1), prepstrict, ba, x, contexts...)
+            @test_throws PME $op!(nothing, mysimilar(res1), prep, ba, x, contexts...)
             scenario_intact && @test new_scen == scen
             return nothing
         end
@@ -179,25 +179,25 @@ for op in ALL_OPS
             reprepare::Bool,
         )
             (; f, x, y, res1, contexts, prep_args) = new_scen = deepcopy(scen)
-            local prepstrict
+            local prep
             preptup_cands_val, preptup_cands_noval = map(1:2) do _
                 prep = $prep_op(f, prep_args.y, ba, prep_args.x, prep_args.contexts...)
-                prepstrict = $prep_op(
+                prep_nostrict = $prep_op(
                     f,
                     prep_args.y,
                     ba,
                     prep_args.x,
                     prep_args.contexts...;
-                    strict=Val(true),
+                    strict=Val(false),
                 )
                 if reprepare &&
                     has_size(x) &&
                     has_size(y) &&
                     (size(x) != size(prep_args.x) || size(y) != prep_args.y)
                     prep = $prep_op!(f, y, prep, ba, x, contexts...)
-                    prepstrict = $prep_op!(f, y, prepstrict, ba, x, contexts...)
+                    prep_nostrict = $prep_op!(f, y, prep_nostrict, ba, x, contexts...)
                 end
-                [(), (prep,), (prepstrict,)]
+                [(), (prep,), (prep_nostrict,)]
             end
             for (preptup_val, preptup_noval) in zip(preptup_cands_val, preptup_cands_noval)
                 y_in1_val = mysimilar(y)
@@ -230,10 +230,8 @@ for op in ALL_OPS
                     @test mynnz(res1_out2_noval) == mynnz(scen.res1)
                 end
             end
-            @test_throws PME $val_and_op(
-                nothing, mysimilar(y), prepstrict, ba, x, contexts...
-            )
-            @test_throws PME $op(nothing, mysimilar(y), prepstrict, ba, x, contexts...)
+            @test_throws PME $val_and_op(nothing, mysimilar(y), prep, ba, x, contexts...)
+            @test_throws PME $op(nothing, mysimilar(y), prep, ba, x, contexts...)
             scenario_intact && @test new_scen == scen
             return nothing
         end
@@ -249,25 +247,25 @@ for op in ALL_OPS
             reprepare::Bool,
         )
             (; f, x, y, res1, contexts, prep_args) = new_scen = deepcopy(scen)
-            local prepstrict
+            local prep
             preptup_cands_val, preptup_cands_noval = map(1:2) do _
                 prep = $prep_op(f, prep_args.y, ba, prep_args.x, prep_args.contexts...)
-                prepstrict = $prep_op(
+                prep_nostrict = $prep_op(
                     f,
                     prep_args.y,
                     ba,
                     prep_args.x,
                     prep_args.contexts...;
-                    strict=Val(true),
+                    strict=Val(false),
                 )
                 if reprepare &&
                     has_size(x) &&
                     has_size(y) &&
                     (size(x) != size(prep_args.x) || size(y) != prep_args.y)
                     prep = $prep_op!(f, y, prep, ba, x, contexts...)
-                    prepstrict = $prep_op!(f, y, prepstrict, ba, x, contexts...)
+                    prep_nostrict = $prep_op!(f, y, prep_nostrict, ba, x, contexts...)
                 end
-                [(), (prep,), (prepstrict,)]
+                [(), (prep,), (prep_nostrict,)]
             end
             for (preptup_val, preptup_noval) in zip(preptup_cands_val, preptup_cands_noval)
                 y_in1_val, res1_in1_val = mysimilar(y), mysimilar(res1)
@@ -309,10 +307,10 @@ for op in ALL_OPS
                 end
             end
             @test_throws PME $val_and_op!(
-                nothing, mysimilar(y), mysimilar(res1), prepstrict, ba, x, contexts...
+                nothing, mysimilar(y), mysimilar(res1), prep, ba, x, contexts...
             )
             @test_throws PME $op!(
-                nothing, mysimilar(y), mysimilar(res1), prepstrict, ba, x, contexts...
+                nothing, mysimilar(y), mysimilar(res1), prep, ba, x, contexts...
             )
             scenario_intact && @test new_scen == scen
             return nothing
@@ -330,17 +328,17 @@ for op in ALL_OPS
             reprepare::Bool,
         )
             (; f, x, y, res1, res2, contexts, prep_args) = new_scen = deepcopy(scen)
-            local prepstrict
+            local prep
             preptup_cands_val, preptup_cands_noval = map(1:2) do _
                 prep = $prep_op(f, ba, prep_args.x, prep_args.contexts...)
-                prepstrict = $prep_op(
-                    f, ba, prep_args.x, prep_args.contexts...; strict=Val(true)
+                prep_nostrict = $prep_op(
+                    f, ba, prep_args.x, prep_args.contexts...; strict=Val(false)
                 )
                 if reprepare && has_size(x) && has_size(y) && (size(x) != size(prep_args.x))
                     prep = $prep_op!(f, prep, ba, x, contexts...)
-                    prepstrict = $prep_op!(f, prepstrict, ba, x, contexts...)
+                    prep_nostrict = $prep_op!(f, prep_nostrict, ba, x, contexts...)
                 end
-                [(), (prep,), (prepstrict,)]
+                [(), (prep,), (prep_nostrict,)]
             end
             for (preptup_val, preptup_noval) in zip(preptup_cands_val, preptup_cands_noval)
                 y_out1_val, res1_out1_val, res2_out1_val = $val_and_op(
@@ -369,8 +367,8 @@ for op in ALL_OPS
                     @test mynnz(res2_out2_noval) == mynnz(scen.res2)
                 end
             end
-            @test_throws PME $val_and_op(nothing, prepstrict, ba, x, contexts...)
-            @test_throws PME $op(nothing, prepstrict, ba, x, contexts...)
+            @test_throws PME $val_and_op(nothing, prep, ba, x, contexts...)
+            @test_throws PME $op(nothing, prep, ba, x, contexts...)
             scenario_intact && @test new_scen == scen
             return nothing
         end
@@ -386,17 +384,17 @@ for op in ALL_OPS
             reprepare::Bool,
         )
             (; f, x, y, res1, res2, contexts, prep_args) = new_scen = deepcopy(scen)
-            local prepstrict
+            local prep
             preptup_cands_val, preptup_cands_noval = map(1:2) do _
                 prep = $prep_op(f, ba, prep_args.x, prep_args.contexts...)
-                prepstrict = $prep_op(
-                    f, ba, prep_args.x, prep_args.contexts...; strict=Val(true)
+                prep_nostrict = $prep_op(
+                    f, ba, prep_args.x, prep_args.contexts...; strict=Val(false)
                 )
                 if reprepare && has_size(x) && has_size(y) && (size(x) != size(prep_args.x))
                     prep = $prep_op!(f, prep, ba, x, contexts...)
-                    prepstrict = $prep_op!(f, prepstrict, ba, x, contexts...)
+                    prep_nostrict = $prep_op!(f, prep_nostrict, ba, x, contexts...)
                 end
-                [(), (prep,), (prepstrict,)]
+                [(), (prep,), (prep_nostrict,)]
             end
             for (preptup_val, preptup_noval) in zip(preptup_cands_val, preptup_cands_noval)
                 res1_in1_val, res2_in1_val = mysimilar(res1), mysimilar(res2)
@@ -440,9 +438,9 @@ for op in ALL_OPS
                 end
             end
             @test_throws PME $val_and_op!(
-                nothing, mysimilar(res1), mysimilar(res2), prepstrict, ba, x, contexts...
+                nothing, mysimilar(res1), mysimilar(res2), prep, ba, x, contexts...
             )
-            @test_throws PME $op!(nothing, mysimilar(res2), prepstrict, ba, x, contexts...)
+            @test_throws PME $op!(nothing, mysimilar(res2), prep, ba, x, contexts...)
             scenario_intact && @test new_scen == scen
             return nothing
         end
@@ -459,23 +457,23 @@ for op in ALL_OPS
             reprepare::Bool,
         )
             (; f, x, y, t, res1, contexts, prep_args) = new_scen = deepcopy(scen)
-            local prepstrict
+            local prep
             preptup_cands_val, preptup_cands_noval = map(1:2) do _
                 prep = $prep_op(f, ba, prep_args.x, prep_args.t, prep_args.contexts...)
-                prepstrict = $prep_op(
+                prep_nostrict = $prep_op(
                     f,
                     ba,
                     prep_args.x,
                     prep_args.t,
                     prep_args.contexts...;
-                    strict=Val(true),
+                    strict=Val(false),
                 )
                 prep_same = $prep_op_same(f, ba, x, map(zero, t), contexts...)
                 if reprepare && has_size(x) && has_size(y) && (size(x) != size(prep_args.x))
                     prep = $prep_op!(f, prep, ba, x, t, contexts...)
-                    prepstrict = $prep_op!(f, prepstrict, ba, x, t, contexts...)
+                    prep_nostrict = $prep_op!(f, prep_nostrict, ba, x, t, contexts...)
                 end
-                [(), (prep,), (prepstrict,), (prep_same,)]
+                [(), (prep,), (prep_nostrict,), (prep_same,)]
             end
             for (preptup_val, preptup_noval) in zip(preptup_cands_val, preptup_cands_noval)
                 y_out1_val, res1_out1_val = $val_and_op(
@@ -498,8 +496,8 @@ for op in ALL_OPS
                     end
                 end
             end
-            @test_throws PME $val_and_op(nothing, prepstrict, ba, x, t, contexts...)
-            @test_throws PME $op(nothing, prepstrict, ba, x, t, contexts...)
+            @test_throws PME $val_and_op(nothing, prep, ba, x, t, contexts...)
+            @test_throws PME $op(nothing, prep, ba, x, t, contexts...)
             scenario_intact && @test new_scen == scen
             return nothing
         end
@@ -515,23 +513,23 @@ for op in ALL_OPS
             reprepare::Bool,
         )
             (; f, x, y, t, res1, contexts, prep_args) = new_scen = deepcopy(scen)
-            local prepstrict
+            local prep
             preptup_cands_val, preptup_cands_noval = map(1:2) do _
                 prep = $prep_op(f, ba, prep_args.x, prep_args.t, prep_args.contexts...)
-                prepstrict = $prep_op(
+                prep_nostrict = $prep_op(
                     f,
                     ba,
                     prep_args.x,
                     prep_args.t,
                     prep_args.contexts...;
-                    strict=Val(true),
+                    strict=Val(false),
                 )
                 prep_same = $prep_op_same(f, ba, x, map(zero, t), contexts...)
                 if reprepare && has_size(x) && has_size(y) && (size(x) != size(prep_args.x))
                     prep = $prep_op!(f, prep, ba, x, t, contexts...)
-                    prepstrict = $prep_op!(f, prepstrict, ba, x, t, contexts...)
+                    prep_nostrict = $prep_op!(f, prep_nostrict, ba, x, t, contexts...)
                 end
-                [(), (prep,), (prepstrict,), (prep_same,)]
+                [(), (prep,), (prep_nostrict,), (prep_same,)]
             end
             for (preptup_val, preptup_noval) in zip(preptup_cands_val, preptup_cands_noval)
                 res1_in1_val = mysimilar(res1)
@@ -567,11 +565,9 @@ for op in ALL_OPS
                 end
             end
             @test_throws PME $val_and_op!(
-                nothing, mysimilar(res1), prepstrict, ba, x, t, contexts...
-            )
-            @test_throws PME $op!(
-                nothing, mysimilar(res1), prepstrict, ba, x, t, contexts...
+                nothing, mysimilar(res1), prep, ba, x, t, contexts...
             )
+            @test_throws PME $op!(nothing, mysimilar(res1), prep, ba, x, t, contexts...)
             scenario_intact && @test new_scen == scen
             return nothing
         end
@@ -587,19 +583,19 @@ for op in ALL_OPS
             reprepare::Bool,
         )
             (; f, x, y, t, res1, contexts, prep_args) = new_scen = deepcopy(scen)
-            local prepstrict
+            local prep
             preptup_cands_val, preptup_cands_noval = map(1:2) do _
                 prep = $prep_op(
                     f, prep_args.y, ba, prep_args.x, prep_args.t, prep_args.contexts...
                 )
-                prepstrict = $prep_op(
+                prep_nostrict = $prep_op(
                     f,
                     prep_args.y,
                     ba,
                     prep_args.x,
                     prep_args.t,
                     prep_args.contexts...;
-                    strict=Val(true),
+                    strict=Val(false),
                 )
                 prep_same = $prep_op_same(f, y, ba, x, map(zero, t), contexts...)
                 if reprepare &&
@@ -607,9 +603,9 @@ for op in ALL_OPS
                     has_size(y) &&
                     (size(x) != size(prep_args.x) || size(y) != prep_args.y)
                     prep = $prep_op!(f, y, prep, ba, x, t, contexts...)
-                    prepstrict = $prep_op!(f, y, prepstrict, ba, x, t, contexts...)
+                    prep_nostrict = $prep_op!(f, y, prep_nostrict, ba, x, t, contexts...)
                 end
-                [(), (prep,), (prepstrict,), (prep_same,)]
+                [(), (prep,), (prep_nostrict,), (prep_same,)]
             end
             for (preptup_val, preptup_noval) in zip(preptup_cands_val, preptup_cands_noval)
                 y_in1_val = mysimilar(y)
@@ -642,10 +638,8 @@ for op in ALL_OPS
                     end
                 end
             end
-            @test_throws PME $val_and_op(
-                nothing, mysimilar(y), prepstrict, ba, x, t, contexts...
-            )
-            @test_throws PME $op(nothing, mysimilar(y), prepstrict, ba, x, t, contexts...)
+            @test_throws PME $val_and_op(nothing, mysimilar(y), prep, ba, x, t, contexts...)
+            @test_throws PME $op(nothing, mysimilar(y), prep, ba, x, t, contexts...)
             scenario_intact && @test new_scen == scen
             return nothing
         end
@@ -661,19 +655,19 @@ for op in ALL_OPS
             reprepare::Bool,
         )
             (; f, x, y, t, res1, contexts, prep_args) = new_scen = deepcopy(scen)
-            local prepstrict
+            local prep
             preptup_cands_val, preptup_cands_noval = map(1:2) do _
                 prep = $prep_op(
                     f, prep_args.y, ba, prep_args.x, prep_args.t, prep_args.contexts...
                 )
-                prepstrict = $prep_op(
+                prep_nostrict = $prep_op(
                     f,
                     prep_args.y,
                     ba,
                     prep_args.x,
                     prep_args.t,
                     prep_args.contexts...;
-                    strict=Val(true),
+                    strict=Val(false),
                 )
                 prep_same = $prep_op_same(f, y, ba, x, map(zero, t), contexts...)
                 if reprepare &&
@@ -681,9 +675,9 @@ for op in ALL_OPS
                     has_size(y) &&
                     (size(x) != size(prep_args.x) || size(y) != prep_args.y)
                     prep = $prep_op!(f, y, prep, ba, x, t, contexts...)
-                    prepstrict = $prep_op!(f, y, prepstrict, ba, x, t, contexts...)
+                    prep_nostrict = $prep_op!(f, y, prep_nostrict, ba, x, t, contexts...)
                 end
-                [(), (prep,), (prepstrict,), (prep_same,)]
+                [(), (prep,), (prep_nostrict,), (prep_same,)]
             end
             for (preptup_val, preptup_noval) in zip(preptup_cands_val, preptup_cands_noval)
                 y_in1_val, res1_in1_val = mysimilar(y), mysimilar(res1)
@@ -721,10 +715,10 @@ for op in ALL_OPS
                 end
             end
             @test_throws PME $val_and_op!(
-                nothing, mysimilar(y), mysimilar(res1), prepstrict, ba, x, t, contexts...
+                nothing, mysimilar(y), mysimilar(res1), prep, ba, x, t, contexts...
             )
             @test_throws PME $op!(
-                nothing, mysimilar(y), mysimilar(res1), prepstrict, ba, x, t, contexts...
+                nothing, mysimilar(y), mysimilar(res1), prep, ba, x, t, contexts...
             )
             scenario_intact && @test new_scen == scen
             return nothing
@@ -742,23 +736,23 @@ for op in ALL_OPS
             reprepare::Bool,
         )
             (; f, x, y, t, res1, res2, contexts, prep_args) = new_scen = deepcopy(scen)
-            local prepstrict
+            local prep
             preptup_cands_val, preptup_cands_noval = map(1:2) do _
                 prep = $prep_op(f, ba, prep_args.x, prep_args.t, prep_args.contexts...)
-                prepstrict = $prep_op(
+                prep_nostrict = $prep_op(
                     f,
                     ba,
                     prep_args.x,
                     prep_args.t,
                     prep_args.contexts...;
-                    strict=Val(true),
+                    strict=Val(false),
                 )
                 prep_same = $prep_op_same(f, ba, x, map(zero, t), contexts...)
                 if reprepare && has_size(x) && has_size(y) && (size(x) != size(prep_args.x))
                     prep = $prep_op!(f, prep, ba, x, t, contexts...)
-                    prepstrict = $prep_op!(f, prepstrict, ba, x, t, contexts...)
+                    prep_nostrict = $prep_op!(f, prep_nostrict, ba, x, t, contexts...)
                 end
-                [(), (prep,), (prepstrict,), (prep_same,)]
+                [(), (prep,), (prep_nostrict,), (prep_same,)]
             end
             for (preptup_val, preptup_noval) in zip(preptup_cands_val, preptup_cands_noval)
                 res2_out1_noval = $op(f, preptup_noval..., ba, x, t, contexts...)
@@ -781,8 +775,8 @@ for op in ALL_OPS
                     end
                 end
             end
-            @test_throws PME $val_and_op(nothing, prepstrict, ba, x, t, contexts...)
-            @test_throws PME $op(nothing, prepstrict, ba, x, t, contexts...)
+            @test_throws PME $val_and_op(nothing, prep, ba, x, t, contexts...)
+            @test_throws PME $op(nothing, prep, ba, x, t, contexts...)
             scenario_intact && @test new_scen == scen
             return nothing
         end
@@ -798,23 +792,23 @@ for op in ALL_OPS
             reprepare::Bool,
         )
             (; f, x, y, t, res1, res2, contexts, prep_args) = new_scen = deepcopy(scen)
-            local prepstrict
+            local prep
             preptup_cands_val, preptup_cands_noval = map(1:2) do _
                 prep = $prep_op(f, ba, prep_args.x, prep_args.t, prep_args.contexts...)
-                prepstrict = $prep_op(
+                prep_nostrict = $prep_op(
                     f,
                     ba,
                     prep_args.x,
                     prep_args.t,
                     prep_args.contexts...;
-                    strict=Val(true),
+                    strict=Val(false),
                 )
                 prep_same = $prep_op_same(f, ba, x, map(zero, t), contexts...)
                 if reprepare && has_size(x) && has_size(y) && (size(x) != size(prep_args.x))
                     prep = $prep_op!(f, prep, ba, x, t, contexts...)
-                    prepstrict = $prep_op!(f, prepstrict, ba, x, t, contexts...)
+                    prep_nostrict = $prep_op!(f, prep_nostrict, ba, x, t, contexts...)
                 end
-                [(), (prep,), (prepstrict,), (prep_same,)]
+                [(), (prep,), (prep_nostrict,), (prep_same,)]
             end
             for (preptup_val, preptup_noval) in zip(preptup_cands_val, preptup_cands_noval)
                 res2_in1_noval = mysimilar(res2)
@@ -851,11 +845,9 @@ for op in ALL_OPS
                     end
                 end
             end
-            @test_throws PME $op!(
-                nothing, mysimilar(res2), prepstrict, ba, x, t, contexts...
-            )
+            @test_throws PME $op!(nothing, mysimilar(res2), prep, ba, x, t, contexts...)
             @test_throws PME $val_and_op!(
-                nothing, mysimilar(res1), mysimilar(res2), prepstrict, ba, x, t, contexts...
+                nothing, mysimilar(res1), mysimilar(res2), prep, ba, x, t, contexts...
             )
             scenario_intact && @test new_scen == scen
             return nothing