Yes, that’s not really the best way to do snapshots TBH and it’s possible to create BTRFS snapshots and also back them up, which is pretty complicated.
I did manage to import a BTRFS snapshot and mount it, but for some reason it messed up some time later - it’s confusing and I just gave up working it out.
I did still have backups to work from, so it didn’t take too long to import what I wanted.