We sometimes find ourselves in a situation where we have made changes to a server TM and discover that the changes were not good.
With file-based TMs, we always create a simple backup copy of the TM and if things go wrong we just delete the faulty one and use the backup.
It would be great if in GS there were a feature to create a "snapshot" or a "backup" of a single TM that DOES NOT involve exporting to TMX and possible restarting from scratch.