I currently use rsync to do encrypted backups to iDrive e2 currently, but I’m concerned about the concept of “syncing isn’t a backup”, since as others have already said here, you can sync corrupted files, accidental deletions, etc. without more than a single snapshot. I’m considering something like Backrest with e2 because I like the idea of something that is opinionated and that “just works” when it comes to backups.