Backup with restic

Hello everybody, I’m doing my file backups with restic so far (for a syncthing/nextcloud combination).

I’m thinking of changing to seafile instead to simplify this (and because of a missing partial (sub)folder sync in syncthing like existing in dropbox). Is it possible to backup also the Seafile files using restic? I would somehow prefer to backup the real files as I’m concerned that I could be not able doing this with the backedup seafile files properly later on. Is there any risk, that I could potentially not be able to extract my files from a seafile backup (made with restic)?

Is there a better way than exporting it via job every night from seafile to a normal file system? We are talking about TB of data and I don’t want to double the storage consumption. Or can I safely just backup the data directory of seafile (even though a restore gets a bit more complicated then maybe)?

And is a backup efficient? As restic has deduplication and transfers only chunks, I hope this will not be broken by seafile’s own storage mechanism?

Real-time backup will be probably not possible this way, as it works only with a second seafile instance, correct?