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
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.