diff --git a/docs/port/DECISIONS.md b/docs/port/DECISIONS.md
index 02c926b5..0372315e 100644
--- a/docs/port/DECISIONS.md
+++ b/docs/port/DECISIONS.md
@@ -4123,3 +4123,50 @@ uncontrolled instrument, but a control chosen where it could not fail.
 fitted. A rotation about a declared pivot rather than the centre would displace by
 roughly that; if it still matters once the association is adopted, it gets
 measured rather than derived.
+
+## Re-running the P5/P6 gate after eight iterations of changes
+
+The leaf path, the plate pulse, the BGM level, the voice export, the focus fix
+and a new diagnostic flag have all landed since the gate was last actually run.
+The mission's test is *"a human presses a d-pad and Ⓐ and moves through those
+screens"*, and I had been verifying pieces of that against captures without once
+re-running the whole walk.
+
+**It works.** Nine steps, unattended:
+
+| step | | |
+|---|---|---|
+| ⬇ ×4 | `ptbtn01` → `ptbtn05` | focus moves, every frame drawn |
+| Ⓐ | `EXTRAS` → screen `extras`, focus `ptbtn11` | |
+| Ⓑ | back to `main_menu`, **focus restored to `ptbtn05`** | HANDOFF Q5's rule, live |
+| ⬆, Ⓐ | `ptbtn04` `OPTIONS`, destination outside this archive | prints the gap rather than pretending |
+
+Filmstrip shared as `1788027380-788b1faafc3e`. Every shot is non-blank (frame
+means 31.5–33.1).
+
+### The sound is verified by a null control, not by a detector
+
+I first tried an onset detector: count sharp level rises in the recording. It
+found **one** onset in the walk — and **the same one** in the music bed alone,
+which contains no cues. The 50 ms envelope cannot see a short cue over the bed.
+⚠️ **The right response to a detector that cannot separate its control from its
+subject is to stop using it**, not to widen the window until the numbers look
+better. That is the shape this session has hit five times.
+
+So the same technique that settled the voice: shadow the three cues with silence
+through `data/mods/`, run the identical walk, and compare.
+
+| | peak | RMS |
+|---|---|---|
+| walk, cues playing | **+0.0003 dBFS** | −18.36 |
+| walk, cues silenced | **−4.74 dBFS** | −20.78 |
+
+**Silencing three sound effects costs 4.74 dB of peak and 2.43 dB of RMS**, and
+the walk's peak is *set by* a cue rather than by the music. The mod log confirms
+exactly three files shadowed. No detector, no threshold, and the control is the
+same run with one input changed.
+
+⚠️ Recorded under the Dummy driver, as everything audio here is. It shows the
+cues reach the Master bus at the right moments; it does not show they are the
+cues the game plays — that is HANDOFF Q8, and `authored/audio.json` still carries
+the offsets as measured rather than decoded.