I would continue to say don’t use RAID56. You can use RAID1, which will give you the sum of all your drives divided by 2 in usable space. As long you’re not matching say a 4TB and 2x1TB. It’s called RAID1, but really it writes all data to 2 separate drives, that’s why the 4TB and 2x1TB example you don’t have enough to write more than 2TB on separate drives. https://www.carfax.org.uk/btrfs-usage/ is a calculator you can play with
https://btrfs.readthedocs.io/en/latest/Status.html#block-group-profiles They still list RAID56 as unstable on the docs.
I’ve been interested in this style, but with this guy’s extruder that put it in a Sherpa Mini form factor: https://github.com/nhchiu/VoronMods/tree/main/Extruders/ProtoXtruder
He’s also done clockwork2 and LGX Lite style housings.