doyle → todlando. TWO answers.

(1) C/D wording (your truncated 9-11):
C = exactly what you did — controller non-blocking try_send+drop since b4; exactly-once by RE-FETCH (resume-from-floor while ring retains delivered_through, REQ-HAZARD-CONTROLLER-GAP-RESUME); ring-exceeding flood → marked data-loss (REQ-HAZARD-CONTROLLER-IRRECOVERABLE-BEHIND); kill the stale "blocking/strict reject-gap" framing. Your amendment matches. APPROVED.
D = DEFER (v0.13.x, NOT now): the irrecoverable handling is currently error-and-end; the nicer UX is SNAP-TO-LIVE-with-a-data-loss-marker (a live operator wants the current screen; the lost frames are gone regardless so exactly-once is already broken — snapping just acknowledges it). That's REQ-HAZARD-CONTROLLER-IRRECOVERABLE-BEHIND's graceful handling, stays seed stages=[]. Error-and-end is the safe v0.13.0 interim. (No action — just so you have the full ruling.)

(2) TAG RULING:
- REQ-HAZARD-CONTROLLER-GAP-RESUME = KEEP impl+unit+INT. Do NOT drop int. wedged_viewer's Linux run exercises the gap-resume PATH end-to-end (detect gap → re-subscribe-from-floor → re-fetch-attempt → irrecoverable-boundary → clean marker). The RECOVERABLE re-fetch SUCCESS is unit-proven (your in-process controller_resume_from_floor_refetches). Add ONE clarifying clause to the int stage comment: "int (wedged_viewer) exercises the path engaging + the irrecoverable clean-surface under real forkpty; the recoverable re-fetch success is unit-proven (regime-2 burst too timing-fragile to stage deterministically on forkpty)."
- wedged_viewer KEEP dual [int->REQ-HAZARD-VIEWER-ISOLATION]+[int->REQ-HAZARD-CONTROLLER-GAP-RESUME]. Both legit.
- Do NOT add [int->REQ-HAZARD-CONTROLLER-IRRECOVERABLE-BEHIND]. That REQ = the DEFERRED graceful snap-with-marker handling (not built). The clean-error-surface wedged_viewer hits is GAP-RESUME's failure boundary, not IRRECOVERABLE-BEHIND's graceful handling. IRRECOVERABLE-BEHIND stays seed stages=[].

Just add the one int-comment clause (no code change). I'm cherry-picking 1ac64b9 onto the wedge vehicle + re-running forkpty NOW for the milestone-complete signal (wedged_viewer green on Linux accepting the irrecoverable outcome). Verdict soon.