NonWonderDog [he/him]

It’s not TOO hard to build a 5- or 8- drive mini-ITX system, and I like my Jonsbo case well enough.

Main issues:

1. mini-ITX server motherboards are expensive (even asrock-rack).
2. mini-ITX server motherboards use OCuLink to connect hard drives. The cables aren’t sold to consumers, and there are two wiring standards for OCuLink-SATA cables that are unmarked (I got lucky on ebay).
3. mini-ITX server motherboards use unbuffered ECC ram in a laptop form factor, which is very specific and again expensive.

So the technical barriers are real.

No, they have it right. Add-on software means “added to this node/machine”, as in not part of the system image used to configure multiple machines. It’s all very archaic.