diff --git a/docs/plans/2026-07-21-per-cluster-mesh-design.md b/docs/plans/2026-07-21-per-cluster-mesh-design.md
index 89f1e22e..addeb661 100644
--- a/docs/plans/2026-07-21-per-cluster-mesh-design.md
+++ b/docs/plans/2026-07-21-per-cluster-mesh-design.md
@@ -165,8 +165,14 @@ Mirror ScadaBridge's shape, adapted to OtOpcUa's existing substrate:
   observability topics with one stream contract carrying a `oneof` event — additive-only field
   evolution, contract-locked by test.
 
-Deliberately **not** copied: their transient-only central alarm cache and site-local-primary storage
-(see §6.1), and their unauthenticated transports (§6.3).
+**Copied:** their node-local configuration store fed by fetch-and-cache (§6.1), their oldest-Up
+active-node rule (§4), their two-node keep-oldest posture including its acknowledged outage gap
+(§6.2), and their unauthenticated inter-cluster transports (§6.3).
+
+**Deliberately not copied:** their *transient-only* central alarm cache. OtOpcUa persists alarm
+history centrally through the historian, and Phase 2's replicated store-and-forward buffer already
+guarantees delivery across a failover — so there is no reason to adopt a design whose stated
+trade-off is that a new active node re-seeds alarm state from scratch.
 
 ## 6. Decisions (settled 2026-07-21)
 
@@ -258,7 +264,7 @@ deserves its own live gate.
   blast radius raised.
 - **`DbHealthProbeActor` feeds a client-visible value.** Removing the driver-side DB connection
   changes what ServiceLevel means on those nodes; that is an interop-visible change, not internal.
-- **The rig currently models the topology that would be abolished.** Phase 4 rewrites
+- **The rig currently models the topology that would be abolished.** Phase 6 rewrites
   `docker-dev/docker-compose.yml` substantially, and every live gate that depends on it.
 - **Losing gossip loses free fleet-wide observability.** Seven AdminUI panels are fed by DPS today;
   each needs an explicit stream and a reconnect story.