Findings custom-formatter-bytes-walked (ruling depth-walk-covers-library-msgpack: the owner skips the walk when the definition carries a formatter; the grey 0x91 image round-trips, plain and codec stay bounded; README says so) and wide-length-unpinned (bin32/str32/ext32 of 65539 bytes and array32/map32 of more than 65535 children before a chain at and past the limit). The same tests pin the inspector refusing to recover a stamp from a past-limit payload. Not yet built.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>