drdexebtjl17 minutes ago
It sounds like most of your frustration can be eliminated by actually using your NAS as the ground-truth for all data, using something like SMB/NFS instead of SyncThing.
Then you only need to backup the NAS.
akersten31 minutes ago
What the author describes here is hard because it's "simple."
What's simple because it's "hard" is replacing parts 2 & 3 with a network appliance like TrueNAS running a zfs pool that syncs to backblaze every night. Yeah you have to learn a bit but it won't fall in weird ways like the hard drive part here will just fail to mount one night and not back things up for 3 months until you notice. My 2¢