diff --git a/03-DESIGN/01-to-be/28-building-the-bus.md b/03-DESIGN/01-to-be/28-building-the-bus.md
index ba1a84e..53ab087 100644
--- a/03-DESIGN/01-to-be/28-building-the-bus.md
+++ b/03-DESIGN/01-to-be/28-building-the-bus.md
@@ -252,7 +252,17 @@ pays for itself furthest away.
       The seam turned out to be eight call sites — the same smallness that said this bus could be
       replaced at all. Still on `*amqp.Channel`: `RequestBuild` and `Ask`, which carry reply-queue
       machinery, and the whole consume side (the control loop, enrolment, serving).
-- [ ] 3.5 the host's link on NATS — mirroring, still importing nothing
+- [~] 3.5 the host's link on NATS — **the outbound half is through a seam**, mirroring the
+      controller's and still importing nothing of the mesh's own (ADR 0005): the host's own
+      interface over its own libraries, agreeing with the controller only because a fixture holds
+      both to one envelope. A report goes through JetStream because it is the message the
+      store-window guarantee is about; a heartbeat stays on core, because a heartbeat in a stream
+      is the mesh's least valuable message competing for retention with its most valuable.
+
+      Still on the old client: dialling, the declaration consumer, and enrolment. The host's
+      **"newest wins" window narrows at the rollout rather than disappearing** — last-per-subject
+      makes catch-up the stream's and sequence orders definitively, but three pushes to a
+      connected node are still three deliveries. Recorded in the code where it is read.
 - [x] 3.6 the tool runtime's client on NATS, behind the unchanged sdk contract — round-tripped
       against a real server: a tool answered across two connections, a throwing handler reaching
       the caller as an error rather than a timeout, an event delivered once with its key, body,