Does TYPO3 automatically recover custom extension table schemas after a failed core upgrade?

When a TYPO3 core upgrade fails after the database migration step, the built‑in rollback mechanism restores the system to the pre‑upgrade backup, but it does not track schema changes made to custom database tables created by third‑party extensions.

Administrators are left to decide whether those tables remain usable, need manual correction, or should be discarded, and there is no documented automated procedure that reverts them to a known good state.

What options, if any, does TYPO3 offer to automatically detect and repair inconsistent custom extension tables after a failed upgrade, and how reliable are those options in practice?