Builds the experimental control Bob correctly identified as still missing after HB-ON/HB-OFF (§XXXIII.5): walk the shuffled matrix of concurrency-level x workload-mode cells, birth the right worker count per cell, drive each with two VM-EXEC touches, check VM-ERROR?, kill them, print a trial marker. Built entirely from existing primitives (WORKER-BIRTH, VM-EXEC, VM-HEAT, VM-ERROR?, KILL, HB-ON/HB-OFF) plus doe.4th's own RUN-MATRIX/SHUFFLE-MATRIX pattern -- no new C primitives. Real capsule-format bug found and fixed: a first draft, chunked purely by a fixed 16-line count with no regard for word boundaries, split several CASE...ENDCASE structures and one oversized colon definition across Block headers. Result was a cascading [CAPSULE][DEFER] failure from the first split forward -- every subsequent line failed to compile, and MU-RUN-TRIAL was never actually defined (confirmed: UNKNOWN WORD when called). Root cause traced to capsule_loader.c directly: a :...; word and any control structure inside it must fit entirely within one 16-line block -- the loader's per-block compile pass has no persistent record of an open CASE's (or an overlong definition's own) state across a Block boundary. Not previously documented anywhere in this project's capsule-authoring guidance. Fixed via manually curated block boundaries and factoring oversized bodies into smaller helper words. Reps ratified at 60/cell (not the 10 first drafted), matching this project's own "rule of 3's" DoE convention (ACL-RWT's 3 seeds/30 reps, std79's 3x9x3). 6 cfgs x 60 reps = 360 main-block trials. MU-MAX-REPS raised 20 -> 63 for run-matrix headroom. Verified live on amd64: one isolated trial (0 0 999 MU-RUN-TRIAL) produced two real concurrent births, two clean kills, and the exact expected marker (MU-TRIAL run=999 cfg=0 rep=0 nw=2 mode=0 fail=0). Hera stayed healthy throughout. Clean 3-arch qemu boot. Not yet run: the full 360-trial MU-EXEC-CAMPAIGN itself (a genuinely long-running action under TCG, deliberately not started without explicit confirmation) or the WIREBIND-automation fixed arm. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01BWpNjdwPtFLuVLaAq44L9K