Proton Drive should be able to recognise or atleast ask you when you install it if you want to asign the backup to an actually backed up host for restoration purposes.

F.E: Someone needs to fully format his PC and when it does it and installs protondrive, the application asks if we want assign and restore from an existing machine backup.

This also will prevent to bloat protondrive storage use and make it a lot more useful.

Also we should be able to delete old machines registered.

This feature is already on Microsoft Onedrive