Mandatory autoland
In the Airline I retired from, the aircraft had to have completed a full Autoland to maintain its Cat III status within the last 60 days. If it had not, it was downgraded to Cat II until a pilot accomplished the fully coupled Autoland and had no problems.
A log entry would be made by the flt crew as to the accomplishment of an autoland with no malfuntions and simply signed off as acknowledged by maintenance and then returned to Cat III status.
If there were problems, it was either downgraded further if needed or repaired.
It would still need the Flight Check to upgrade.