run 28

docs/pt2-protocol-summary.md

@@ -294,6 +294,11 @@ Current caution:
   `90` opened `E8`, `E9`, and `EC`; `AF` opened `E9` and `EC`, and shifted
   `E8` into the sibling `07 80 FA 50 26 51` family; bare heartbeat opened `E8`
   and `E9` but not `EC`.
+- Downstream-behavior follow-ups suggest opener choice changes the selector
+  result more than the reply ladder:
+  `90 -> E8` yielded sibling `07 80 7A 58 26 D9`, `90 -> EC` yielded sibling
+  `07 80 FB 50 26 50`, but the downstream exact echoes still collapsed to
+  heartbeat.
 
 ## What We Know
 
@@ -334,6 +339,8 @@ Current caution:
 - There appears to be a small family of context openers rather than a single
   magic gate byte; `EC` is stricter than `E8/E9`, and heartbeat alone was not
   enough to open it.
+- At the moment, opener bytes look more like family/page selectors than like
+  things that enable a stable multi-turn conversation after the first response.
 
 ## What We Do Not Know