I run unraid with 30 disks. Most are in the 18 to 22tb range. It works pretty well, but parity rebuilds take 4 days or so when I replace a disk. Much longer if I’m writing large amounts of data as well.

Biggest issue is that your parity disks must always be your largest disks. So you’d need 2 of these to make it worth it (if your only using a single disk for parity.) Which makes jumping into them pricey.