After a lot of work, and a lot of trying, I couldn’t find FOSS software that properly syncs my family’s photos in the background (tried Immich, still not good enough despite the new beta timeline, kinda worked in 1.136, got kinda broken on 1.138, tried Nextcloud, but still haven’t gotten new photos to sync in the background. Ente is waaaay too complicated, with waaaay too many moving parts that can break). Given all of this, I gotta choose some prebuilt nas that can properly sync. I don’t like synology but apparently their background sync is ok. What about Qnap and Ugreen? Are they ok?
I was using PhotoSync quite successfully until I’ve switched to iCloud.
Nowadays, my MacBook is configured to always download all photo originals. And my Photo Library is then backed up to my NAS using CCC. This allows easy restore in case something goes wrong, as I can either restore the whole library or open the backup library and pull out what’s needed. If that fails, there’s also osxphotos to work with the library.