Docs: record Phase Upsilon W1; carry forward W2/W3 constraints; SEPT_VERIFY section 7

docs/SEPT_VERIFY.md

@@ -111,3 +111,16 @@ project rate 48000, unless a check says otherwise.
   one is available) — the editor title shows the refusal message, the sample plays silent, the
   message clears when another sample is loaded, and a bake shows "cannot render"
 - [ ] The refusal text is not truncated at the default editor width
+
+## 7. ReaSampler 9000 finds samples in its own project (landed Sept 2026)
+
+- [ ] Open two projects in tabs, each with a ReaSampler 9000 on a different bank sample; switch
+  tabs — each instance plays its own sample, including the one in the background tab
+- [ ] Open a saved project containing ReaSampler 9000 into a NEW tab — the instance plays (not
+  silent)
+- [ ] Same, via File → Open into the CURRENT tab
+- [ ] Render the project via the render queue — the instrument is audible in the render
+- [ ] Render a project that is used as a subproject — the instrument is audible
+
+For the last four: if any comes up silent until the sample is re-selected, report it (a retry is
+the planned fix).