I recently set up something similar to this. I can’t comment on your specific hardware, but I was very frustrated with the limitations of TrueNAS and ended up using Debian and Cockpit with BTRFS for the drives.
I started with two 18TB drives with no RAID, and have since added two 26TB drives with everything’s using RAID1 and ~45TB of usable storage. Converting and adding drives was very simple, but also time consuming of course.







They absolutely did exist in the 20th century, but they were much heavier and bulky, used resistive touch screens, had awful battery life, and were understandably very primitive compared to modern tablets.