This is not a SFW instance. NSFW communities will be tagged, and efforts will be made to keep SFW communities clean, but proceed at your own comfort level.
You could set them up to run a Restic server for you and then do backups with that. Restic is fully encrypted, does differential backups, and can do configurable pruning. With 4 TB the initial run will take long, even locally, but it can also resume, so should work.
You could set them up to run a Restic server for you and then do backups with that. Restic is fully encrypted, does differential backups, and can do configurable pruning. With 4 TB the initial run will take long, even locally, but it can also resume, so should work.
https://github.com/restic/rest-server