Apple Support, in an ancient article:
After initializing a hard disk with a 4096 byte block size using FWB Hard Disk Took kit, I could not initialize the volume with Apple RAID 1.5 because the block size was greater than 512 bytes.
Apple RAID does not support these drives, as 512 is the standard maximum for block sizes. It will allow you to format them, but that’s all. No volumes, no mounts, no driver support. This is as designed.
Happy 5/12 day, if you put the month in front of the date when you write it. If not, we can celebrate again in December.