diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index a8818d1f9..f33dfb25d 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -122,7 +122,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout VERSION file and tag history
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           sparse-checkout: VERSION
           fetch-depth: 0 # Get all history regarding tags.  We'll need that for VERSION checking below.
@@ -229,6 +229,7 @@ jobs:
             version: 9
             c-path: /usr/bin/gcc-9
             cpp-path: /usr/bin/g++-9
+            install: True
           - id: gcc-10
             name: gcc
             version: 10
@@ -628,7 +629,7 @@ jobs:
       run: pip install 'conan<2'
 
     - name: Checkout `ipc` repository and submodules (`flow`, `ipc_*`)
-      uses: actions/checkout@v4
+      uses: actions/checkout@v6
       with:
         submodules: true
 
@@ -903,7 +904,7 @@ jobs:
         $BUILT_CMD_PREFIX \
           ./ipc_session_link_test_srv.exec $OUT_DIR/srv.log > $OUT_DIR/srv.console.log 2>&1 &
         SRV_PID=$!
-        sleep 1
+        sleep 5
         $BUILT_CMD_PREFIX \
           ./ipc_session_link_test_cli.exec $OUT_DIR/cli.log > $OUT_DIR/cli.console.log 2>&1
         if wait $SRV_PID; then SRV_EC=0; else SRV_EC=$?; fi
@@ -927,7 +928,7 @@ jobs:
         $BUILT_CMD_PREFIX \
           ./ipc_shm_link_test_srv.exec $OUT_DIR/srv.log > $OUT_DIR/srv.console.log 2>&1 &
         SRV_PID=$!
-        sleep 1
+        sleep 5
         $BUILT_CMD_PREFIX \
           ./ipc_shm_link_test_cli.exec $OUT_DIR/cli.log > $OUT_DIR/cli.console.log 2>&1
         if wait $SRV_PID; then SRV_EC=0; else SRV_EC=$?; fi
@@ -953,7 +954,7 @@ jobs:
         $BUILT_CMD_PREFIX \
           ./ipc_shm_arena_lend_link_test_srv.exec $OUT_DIR/srv.log > $OUT_DIR/srv.console.log 2>&1 &
         SRV_PID=$!
-        sleep 1
+        sleep 5
         $BUILT_CMD_PREFIX \
           ./ipc_shm_arena_lend_link_test_cli.exec $OUT_DIR/cli.log > $OUT_DIR/cli.console.log 2>&1
         if wait $SRV_PID; then SRV_EC=0; else SRV_EC=$?; fi
@@ -1054,7 +1055,7 @@ jobs:
         $BUILT_CMD_PREFIX \
           ./perf_demo_srv_$1.exec 1000 $OUT_DIR/srv.log > $OUT_DIR/srv.console.log 2>&1 &
         SRV_PID=$!
-        sleep 20 # It fills up a large structure before listening, so give it some time (mostly for slow build types).
+        sleep 40 # It fills up a large structure before listening, so give it some time (mostly for slow build types).
         $BUILT_CMD_PREFIX \
           ./perf_demo_cli_$1.exec $OUT_DIR/cli.log > $OUT_DIR/cli.console.log 2>&1
         if wait $SRV_PID; then SRV_EC=0; else SRV_EC=$?; fi
@@ -1106,7 +1107,7 @@ jobs:
           ./transport_test.exec scripted $OUT_DIR/srv.log info $1 \
           < srv-script.txt > $OUT_DIR/srv.console.log 2>&1 &
         SRV_PID=$!
-        sleep 1
+        sleep 5
         $BUILT_CMD_PREFIX \
           ./transport_test.exec scripted $OUT_DIR/cli.log info $1 \
           < cli-script.txt > $OUT_DIR/cli.console.log 2>&1 &
@@ -1282,7 +1283,7 @@ jobs:
     - name: Upload test/demo logs (please inspect if failure(s) seen above)
       if: |
         always()
-      uses: actions/upload-artifact@v4
+      uses: actions/upload-artifact@v7
       with:
         name: ipc-test-logs-${{ matrix.compiler.id }}-${{ matrix.build-test-cfg.id }}-${{ matrix.cxx-std.id }}
         path: ${{ env.install-dir }}/bin/logs.tgz
@@ -1334,9 +1335,11 @@ jobs:
       run: pip install 'conan<2'
 
     - name: Checkout `ipc` repository and submodules (like `flow`)
-      uses: actions/checkout@v4
+      uses: actions/checkout@v6
       with:
         submodules: true
+        # Avoids the duplicate-authorization-error in (not-frequently-invoked) doc_check_in step later down.
+        persist-credentials: false
 
     # In our process (and this is typical, though it is also possible to create tag without release) we
     # hit Publish on a new Release in GitHub; and this creates both the Release and tag, by convention both named
@@ -1474,7 +1477,7 @@ jobs:
           ${{ github.workspace }}/build/${{ matrix.build-cfg.conan-profile-build-type }}
 
     - name: Upload documentation tarball
-      uses: actions/upload-artifact@v4
+      uses: actions/upload-artifact@v7
       with:
         name: ipc-doc
         path: ${{ github.workspace }}/doc/ipc_doc.tgz
diff --git a/flow b/flow
index a0e39611f..17273d087 160000
--- a/flow
+++ b/flow
@@ -1 +1 @@
-Subproject commit a0e39611f798742a77bad2d73b66ef9bf2a1ef66
+Subproject commit 17273d087ac30dcdfdc69610280cd430464248ad
diff --git a/ipc_core b/ipc_core
index cece0c5a6..98ad2a09f 160000
--- a/ipc_core
+++ b/ipc_core
@@ -1 +1 @@
-Subproject commit cece0c5a6b157a9df92aa0cb8404642792c07ea3
+Subproject commit 98ad2a09f8cee0bd45939588d2e56b72ebf24209
diff --git a/ipc_session b/ipc_session
index 6946059e0..14f82cb12 160000
--- a/ipc_session
+++ b/ipc_session
@@ -1 +1 @@
-Subproject commit 6946059e017878b2590f95bb8c4b6abcdc752601
+Subproject commit 14f82cb12bce81b073097f3b4a53a1cadd29d651
diff --git a/ipc_shm b/ipc_shm
index eef36d5d7..b9f2b8d14 160000
--- a/ipc_shm
+++ b/ipc_shm
@@ -1 +1 @@
-Subproject commit eef36d5d7c16d5841c69b58de8f13238726fe777
+Subproject commit b9f2b8d148f94e84ab05ea1839107263ec272dfe
diff --git a/ipc_shm_arena_lend b/ipc_shm_arena_lend
index 870676d8b..3f18295c2 160000
--- a/ipc_shm_arena_lend
+++ b/ipc_shm_arena_lend
@@ -1 +1 @@
-Subproject commit 870676d8bc07d5f7f76948bfb4a5b29d68e2ebeb
+Subproject commit 3f18295c2231735b50d1d25c66fcec7a5c2d3423
diff --git a/ipc_transport_structured b/ipc_transport_structured
index 3d01389a2..61469c6ce 160000
--- a/ipc_transport_structured
+++ b/ipc_transport_structured
@@ -1 +1 @@
-Subproject commit 3d01389a26687bd835d29e1b285114e453aa25d7
+Subproject commit 61469c6ce6abfc83a7601389bbc3d301b1e3641b
diff --git a/test/suite/unit_test/CMakeLists.txt b/test/suite/unit_test/CMakeLists.txt
index 19d2e1c38..c80afba08 100644
--- a/test/suite/unit_test/CMakeLists.txt
+++ b/test/suite/unit_test/CMakeLists.txt
@@ -108,6 +108,7 @@ set(SRCS
     ${isal_root}/ipc/shm/arena_lend/test/test_owner_shm_pool_collection.cpp
     ${isal_root}/ipc/shm/arena_lend/test/test_shm_object.cpp
     ${isal_root}/ipc/shm/arena_lend/test/test_shm_pool_collection.cpp
+    ${isal_root}/ipc/shm/test/lend_borrow_test.cpp
     test_main.cpp)
 set(CAPNP_SCHEMAS
     ${isal_root}/ipc/session/standalone/shm/arena_lend/jemalloc/test/test_message.capnp