Seedvault has the concept of time-based snapshots and when to prune them - the snapshots are logged to a file in the backup directory (“repository”). It’s not user exposed but is set to:
By default we keep 3 daily snapshots and 2 weekly ones (one from this and one from last week) (1 or source)
Here is the snapshot doc section that explains the format and storage design docs.
Problem is, this is the android15-branch docs (but is backported to A14) - /e/ ships a very old prebuilt apk. One cannot contribute prebuilt apks. I’m being a nuisance about this since I opened this thread.