diff --git a/README.md b/README.md
index d0da2f5..39cea25 100644
--- a/README.md
+++ b/README.md
@@ -143,7 +143,7 @@ The first five settings are required when the controller file exists.
 | `cooldown_secs` | `30` | Per-VM pause after a successful scale action. |
 | `max_instances_adjusted_per_poll` | `0` | Most VMs resized per poll; `0` means no limit. |
 | `dry_run` | `false` | Log decisions without resizing pools. |
-| `enable_per_vm_status_line` | `true` | Write a status line per VM every poll. |
+| `enable_per_vm_status_line` | `false` | Write a status line per VM every poll. |
 | `enable_per_vm_main_log` | `false` | Send per-VM status lines to the main log instead of per-VM files. |
 | `enable_aggregate_status_line` | `true` | Write one fleet-wide status line every poll. |
 | `print_status_header` | `false` | Log a legend of the status-line fields at startup. |
diff --git a/io-thread-controller.d/engines/threshold.json b/io-thread-controller.d/engines/threshold.json
index 110084e..94792de 100644
--- a/io-thread-controller.d/engines/threshold.json
+++ b/io-thread-controller.d/engines/threshold.json
@@ -2,7 +2,7 @@
   "scale_up_threshold_percent": 95,
   "scale_down_sustain_secs": 120,
   "max_scale_down_step": 0,
-  "scale_up_min_gain_percent": 5,
+  "scale_up_min_gain_percent": 1,
   "scale_down_revert_drop_percent": 3,
   "scale_validation_delay_secs": 30,
   "scale_validation_delay_per_thread_secs": 0,
diff --git a/io-thread-controller.json b/io-thread-controller.json
index 9efee46..ed369fb 100644
--- a/io-thread-controller.json
+++ b/io-thread-controller.json
@@ -1,12 +1,13 @@
 {
-  "scale_poll_secs": 10,
+  "scale_poll_secs": 5,
   "round_up_durations": false,
-  "enable_per_vm_status_line": true,
+  "enable_per_vm_status_line": false,
+  "enable_per_vm_main_log": false,
   "enable_aggregate_status_line": true,
   "min_thread_count": 1,
-  "max_thread_count": 8,
+  "max_thread_count": 16,
   "host_cpu_scale_up_ceiling_percent": 90,
-  "cooldown_secs": 10,
+  "cooldown_secs": 30,
   "engine": "threshold",
   "engine_config_dir": "/etc/io-thread-controller.d/engines",
   "backend_config_dir": "/etc/io-thread-controller.d/backends",
diff --git a/src/config.rs b/src/config.rs
index 9e4b415..4a24601 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -76,10 +76,11 @@ pub struct Config {
     #[serde(default)]
     pub round_up_durations: bool,
     /// Emit a `vm=<id>` status line per tracked instance on
-    /// every tick (default `true`).
-    #[serde(default = "default_true")]
+    /// every tick (default `false`).
+    #[serde(default)]
     pub enable_per_vm_status_line: bool,
-    /// Also emit each per-VM status record on the main controller target.
+    /// Also emit each per-VM status record on the main controller target (default `false`).
+    /// Has no effect is `enable_per_vm_status_line` is `false`.
     #[serde(default)]
     pub enable_per_vm_main_log: bool,
     /// Emit a single aggregate status line summarising every
@@ -242,7 +243,7 @@ impl Default for Config {
             host_cpu_scale_up_ceiling: 0.9,
             cooldown_secs: default_cooldown_secs(),
             vm_state_path: Path::new("/run/io-thread-controller/vm-ownership.json"),
-            enable_per_vm_status_line: true,
+            enable_per_vm_status_line: false,
             enable_per_vm_main_log: false,
             enable_aggregate_status_line: true,
             print_status_header: false,