diff --git a/docs/plans/2026-06-27-otopcua-historian-followups.md b/docs/plans/2026-06-27-otopcua-historian-followups.md
index 4e2a1672..7b91dea2 100644
--- a/docs/plans/2026-06-27-otopcua-historian-followups.md
+++ b/docs/plans/2026-06-27-otopcua-historian-followups.md
@@ -166,7 +166,12 @@ T19 pruned the Wonderware-shaped fields and reworked `AlarmHistorianRegistration
 covered by a test (the sibling warnings for `DrainIntervalSeconds`/`Capacity`/`DeadLetterRetentionDays`
 are). Add a `Validate_warns_on_non_positive_max_attempts` case. Trivial.
 
-### FU-5 — Pre-existing `Host.IntegrationTests` failure (NOT ours — track separately)
+### FU-5 — Pre-existing `Host.IntegrationTests` failure (NOT ours) — ✅ TRACKED via Gitea issue [#424](https://gitea.dohertylan.com/dohertj2/lmxopcua/issues/424) (2026-06-27)
+> **Outcome:** re-confirmed pre-existing — the test still fails (`Accepted` expected, `Rejected` actual) and
+> `git diff --stat master..HEAD` shows this branch touches **none** of the Modbus/`DraftValidator`/
+> `ConfigComposer`/equipment-materialization path. Filed as a standalone tracking issue (#424) so the
+> `DraftValidator` rejection root-cause is owned separately from the historian work. No code change here.
+
 `EquipmentNamespaceMaterializationTests.Deploying_an_equipment_namespace_carries_the_signal_into_the_artifact`
 fails (`Rejected` vs expected `Accepted`) on a **Modbus-only** namespace via `DraftValidator`/
 `ConfigComposer` — untouched by this branch. **Verified failing identically on `master`** (via