This writable enumerated value configures whether the APS group automatically reverts traffic back to the working line once it recovers (on) or stays on whichever line is currently active (off). Admins set this based on whether they want automatic failback after a working-line repair, which avoids leaving traffic stranded on the protection line indefinitely but can also cause a second brief interruption when it reverts. For example, an admin who prefers to manually control failback after fiber repairs would set apsRevertMode to off(2) so traffic stays on the protection line until they explicitly issue a switch command.