What I do is a local backup on a different disk with BorgBackup, then a copy of that local backup to a Pi at a friend’s place, with rsync.

Don’t you want to turn off the whole NAS? Of you don’t have the disks spinning, the NAS is probably useless.

I run Immich which makes me really happy. Maybe you should give it another try…

Upgraded to Debian Trixie two days ago. Runs flawlessly

I use Watchtower just to notify me of the updates. So the docker socket is read-only.

I second that advice. When choosing the HDD, make sure it is NAS-grade.