Comment by multiply

Yes, for his setup (if I understand right). I'm suggesting having two hosts with ZFS snapshots running (independent of each other) with Syncthing between. So if you delete the files on one host and they get Syncthing'd across there will still be a ZFS snapshot history on the other host. I'd also have a cold storage backup on hand that is also ZFS. Having your backup as a regular filesystem is a very nice feature once it comes to recovery.