After re-reading the base version, the two candidates address different failure surfaces and can coexist, but neither is proven by executed crash-recovery tests. All assessment below is reasoning from the published procedure and its stated gap analysis only.
Improvement A sharpens the ambiguous crash-after-rename boundary with a concrete timeline. The base text already names this class and gives a separate reasoned example for false baseline capture from an orphan that differs from the published fragment. A would add a second worked timeline where the orphan bytes match the caller expected baseline, the published fragment holds different bytes, and the published modification time is newer than the orphan. That combination matters because the superseded-attempt rule invites agents to lean on age ordering, yet newer published mtime does not prove rename completed when byte content and expected baseline disagree. A would spell out why fail-closed deletion stays mandatory and list contract-allowed evidence an operator must consult before any gate starts, such as a recorded publish receipt, a post-rename verification log from the prior attempt, or an explicit monotonic attempt counter in the temp name. Limitations of A: it does not reduce wrong-source rename when two orphans remain and classification is already unambiguous; it does not address clock skew or restored backups that reset published mtime; it does not serialize concurrent writers; and it still leaves the operator path manual when evidence is missing. A primarily improves decision quality on the fail-closed branch rather than throughput on the happy path.
Improvement B adds an independent pre-gate verification pass after orphan removal and before ownership or expected-byte gates. Steps would re-list contract attempt temps, re-stat the published fragment with no-follow semantics, and confirm byte length and digest still match values captured at reconciliation start, aborting gate entry on any drift. This targets time-of-check-time-of-use gaps between the initial read during classification and gate entry, including a concurrent writer dropping a new orphan or mutating the published fragment after reconciliation finished. Limitations of B: it does not resolve ambiguous classification when orphan bytes disagree with published bytes and expected baseline alignment is unclear; it does not replace writer serialization called out as out of scope; a narrow race can still exist between the second digest check and the first gate syscall unless paired with external locking; and agents may confuse it with adjacent post-rename verification, which runs after a successful rename in the current attempt rather than before gates at the next operation start. B is most valuable when reconciliation performs deletions and the managed directory is shared, not when every orphan was already classified ambiguous with no removals.
Comparative note: A and B are independent. A clarifies when to stop and escalate; B adds a sanity check on the path that proceeds. Neither substitutes for publish gates, post-rename verification in the current attempt, or external serialization. No filesystem crash, kill, or recovery tests were executed for this assessment; prioritizing A versus B for the next edit remains a judgment call pending either executed tests or operator feedback from real ambiguous cases.