run 24

docs/pt2-protocol-summary.md

@@ -242,6 +242,7 @@ confirmed Sony definition.
 | `07 80 7A 50 26 D1` | host-shaped `E8` branch, reproduced across HE8-HE11 group 1 | medium-high | reproducible downstream response family in the `E8` / `FA` / `7A` branch |
 | `07 80 7A 28 D3 5C` | host-shaped `E9` neighbor, group 1 | low-medium | nearby distinct `7A`-family response; suggests an `E8`/`E9` selector neighborhood |
 | `07 80 7B 50 26 D0` | host-shaped `EC` neighbor, group 1 | low-medium | new sibling family suggesting the `Ex` region is a selector-like strip |
+| `07 C0 2F 95 09 2E` | exact echo of `07 80 7B 50 26 D0`, group 1 | low-medium | possible second-stage family on the `EC -> 7B` branch |
 
 Current caution:
 
@@ -272,6 +273,9 @@ Current caution:
 - Extending outward reinforced the selector-strip model:
   `E6` and `EB` fall into the `07 80 40 40 30 ED` transient family, while `EC`
   opens a new `07 80 7B 50 26 D0` sibling response.
+- `EC` is now the first branch where the exact downstream echo looks more
+  meaningful than the host-shaped mirror: exact `07 80 7B 50 26 D0` produced
+  `07 C0 2F 95 09 2E`, while host-shaped `00 00 7B 50 26 57` did not.
 
 ## What We Know
 
@@ -304,6 +308,8 @@ Current caution:
 - The wider `Ex` region now looks like a mixed selector surface:
   some values collapse into heartbeat-family transients, while others open
   related `7A` / `7B` downstream families.
+- The `EC -> 7B` path is currently the strongest sign that some downstream
+  exact echoes may matter, even though most earlier `7A`-family echoes did not.
 
 ## What We Do Not Know