diff --git a/docs/qa-modes-bench.md b/docs/qa-modes-bench.md
index f336268..a3b5233 100644
--- a/docs/qa-modes-bench.md
+++ b/docs/qa-modes-bench.md
@@ -205,3 +205,51 @@ Findings relevant to this journal's per-mode recommendations:
 See `docs/tickets/ticket-000008-broad-quantifier-preflight-guard.md`
 §12 for the four-cell data and the §10.8 decision-tree verdict.
 Bench artifacts: `bench/qa_results/2026-05-03T12-{29-53,38-53,47-23,54-11}Z.{jsonl,md}`.
+
+### Addendum 2 — preflight ON vs OFF validation (2026-05-03T23-06-21Z)
+
+After ticket #000010 flipped `quantifier_reminder_enabled=True` and
+shipped `metacognition_enabled=True` defaults, ran a preflight-OFF
+cell to validate the flip didn't regress baseline behavior. Same
+9-question broad subset (`bench/qa_questions_quantifier_subset.txt`),
+n=3, policy override
+`--policy metacognition_enabled=false --policy quantifier_reminder_enabled=false`.
+
+Compared against §12.6 reminder-only baseline (cleanest single-knob
+on-cell). On this 9-question subset, none of the metacognition
+detectors fire (no temporal / contradiction / false-premise / out-
+of-corpus shapes), so the comparison effectively isolates the
+reminder contribution.
+
+| Metric                       | OFF       | ON        | Δ        |
+|------------------------------|-----------|-----------|----------|
+| `quote` strict-rate          | 0.63      | 0.52      | −11pp (noise band on 27 samples) |
+| `pointer` strict-rate        | 0.00      | 0.00      | 0        |
+| `JSON` strict-rate           | 0.26      | 0.22      | −4pp     |
+| **`pointer` mean ratio**     | 0.483     | **0.643** | **+16pp** |
+| **`JSON` mean ratio**        | 0.570     | **0.735** | **+17pp** |
+| **`JSON` UNGROUNDED rate**   | 7/27 (26%) | **1/27 (4%)** | **−22pp** |
+| **`pointer` FORMAT_COLLAPSED** | 2/27   | **0/27**  | **−100%** |
+| `pointer` NO_EVIDENCE_POINTER | 8/27    | 6/27      | −7pp     |
+
+**Interpretation:**
+
+- **Mean-ratio improvement is robust** (+16-17pp on lattice modes).
+  Grounded rows are MORE thoroughly grounded under preflight ON.
+- **JSON UNGROUNDED collapse is dramatic** (−22pp). The "didn't
+  ground" pool reclassifies into "partially grounded" — operator-
+  visible win.
+- **FORMAT_COLLAPSED elimination on pointer mode** (2 → 0). The
+  reminder restates the [E\d+] citation rule and Hermes follows
+  it.
+- **STRICT-rate moves are within noise.** Quote-mode dipped 11pp,
+  but quote is mode-gated off the guard so this is pure Hermes
+  nondeterminism — the §10.8 5pp floor exists exactly to filter
+  this. JSON SR moved −4pp (within floor).
+
+**Verdict:** the #000010 default-on flip is doing what was
+claimed. Mean-ratio + UNGROUNDED + FORMAT_COLLAPSED metrics all
+improve by ≥5pp on lattice modes; STRICT-rate is within noise.
+Defaults stay on.
+
+Bench artifact: `bench/qa_results/2026-05-03T23-06-21Z.{jsonl,md}`.
diff --git a/docs/tickets/ticket-000010-metacognition-preflight-guard.md b/docs/tickets/ticket-000010-metacognition-preflight-guard.md
index ab0e958..33d4fed 100644
--- a/docs/tickets/ticket-000010-metacognition-preflight-guard.md
+++ b/docs/tickets/ticket-000010-metacognition-preflight-guard.md
@@ -461,3 +461,33 @@ Follow-ups split into separate tickets:
 
 This ticket file remains in place as the design log per
 `docs/TICKETS.md` convention.
+
+### 13.1 Default-flip validation bench (2026-05-03T23-06-21Z)
+
+Post-landing validation: ran a preflight-OFF cell on the
+9-question broad subset (`metacognition_enabled=false`,
+`quantifier_reminder_enabled=false`) to confirm the §12.10 default
+flip wasn't a regression. Compared against §12.6 reminder-only
+baseline.
+
+| Metric                       | OFF       | ON        | Δ        |
+|------------------------------|-----------|-----------|----------|
+| pointer mean ratio           | 0.483     | **0.643** | **+16pp** |
+| JSON mean ratio              | 0.570     | **0.735** | **+17pp** |
+| JSON UNGROUNDED rate         | 7/27 (26%) | **1/27 (4%)** | **−22pp** |
+| pointer FORMAT_COLLAPSED     | 2/27      | **0/27**  | **−100%** |
+| pointer NO_EVIDENCE_POINTER  | 8/27      | 6/27      | −7pp     |
+| any-mode STRICT-rate         | within ±11pp noise band on 27-sample cells |
+
+**Verdict:** defaults stay on. Mean-ratio + UNGROUNDED + FORMAT_
+COLLAPSED metrics all clear the 5pp signal floor on lattice modes;
+STRICT-rate moves are within Hermes nondeterminism for n=3.
+
+On this subset the metacognition detectors don't fire (no
+temporal / contradiction / false-premise / out-of-corpus shapes),
+so the delta isolates the reminder contribution. A future bench
+cycle on a metacog-trigger subset would isolate the metacog
+contribution; deferred.
+
+Bench artifact: `bench/qa_results/2026-05-03T23-06-21Z.{jsonl,md}`.
+Documented in `docs/qa-modes-bench.md` Addendum 2.