@olivierlambert we are thinking about implementing a relationnal DB in the future. Maybe it could offer to stock snapshots as "archived"... I don't know for now.
I understand that it could be risky to delete old snapshots, and maybe the responsability of setting the snaspshots retention can be an ACL subject...
There are plenty of avenues of work on this topic, and more generally on the retention of information about objects, tasks, and other actions. It's a real in-depth topic.