Hello Jay Jay

1. i think the disk will definitely work. Synology always takes a while to add the current largest disks to the compatibility list. Don't have any experience with Xpenology, but don't see any reason why they should have restrictions. The only thing to note is that with Synology (and Xpenology?) you can't use more than 108TB per volume.

At Backblaze, the disk with a small number of units and little runtime was in the latest report with a poor AFR (Average Failure Rate). I only discovered this after buying two of them *#/&%* I just hope that they had a couple of "Monday models" in there and that the general statistics of the hard disks will improve over time.
https://www.backblaze.com/blog...

3. bought my second server with i3 processor (power saving and h265 encoding support for Plex) and ECC RAM a few weeks ago, so I can now mirror my first FreeNAS/TrueNAS at a second location. It took a bit of a learning curve for me as a non computer scientist and non Unixer and not a big terminal user, but it was worth it. ZFS has its hurdles here and there, but has snapshots, checksum and everything else you could wish for. With iocage, you build your own jailed server for each application. I now run three Nextcloud, Plex, Reverse Proxy, DNS with VoidZones, TimeMachine, UnifiController and one or two other things. Btw, I already had an old Synology as a backup (admittedly 415play plastic box), but actually only want ZFS (btrfs unfortunately doesn't run on 415play).

As for hardware, TrueNAS has so far eaten all the PCI cards (I wouldn't put the WLAN on it) that I have installed. But I would definitely use ECC Ram with ZFS. I have read various things about this, but it seems to be rather negligent.

Good luck and have fun