I found one blocking data-correctness issue in the recycler default change.

Critical checkpoint conclusions:

• Goal and proof: The diff changes both recycler ownership-safety defaults to false and adapts tests, but every changed lifecycle test forces the previous true/true behavior and does not prove the shipped false/false path safe.
• Scope and clarity: The source change is small, but it removes a correctness-sensitive claim-before-delete protocol without an equivalent fence or a rationale in the PR body.
• Concurrency: Blocking issue found. PREPARE-to-tmp promotion can race with queued object deletion, and an eventual transaction left COMMITTED can lose all tmp rows before lazy finalization and still become VISIBLE.
• Lifecycle/static initialization: The test guard has safe stack lifetime and restores both globals. The relevant production lifecycle is the deferred COMMITTED-to-VISIBLE transition; no separate static-initialization issue was found.
• Configuration: Both flags are mutable. recycle_tmp_rowsets() observes them in every NORMAL instance mode, while the non-versioned recycle_rowsets() path also loses the fence.
• Compatibility and parallel paths: Versioned ref-count cleanup, retention delays, rolling instance modes, and compaction/schema-change job checks do not provide equivalent ownership. No wire or storage-format incompatibility was found.
• Conditional/error handling: Disabling the mark and abort gates is the blocking condition; no separate error-propagation issue was substantiated.
• Tests/results: The nine guarded lifecycle tests continue to validate true/true only, and existing false/false recycler tests are uncontended. I did not run builds or tests because this review runner explicitly forbids them.
• Observability: Existing logs can trace these paths, but observability does not prevent the race; no separate logging blocker was found.
• Persistence and data writes: Formal or tmp metadata can survive while its object files are deleted, and a transaction can become VISIBLE after its tmp metadata and files are gone.
• Performance: No distinct performance regression was substantiated.

User focus: No additional user-provided review focus was specified.

Review completion: The full two-file authoritative diff and upstream/downstream paths were reviewed. Three rounds of normal and risk-focused review converged; every Round 3 reviewer returned NO_NEW_VALUABLE_FINDINGS against this exact frozen payload, and no suspicious point remains unresolved.