I'm no expert either. However, I read that there are different M.2 interfaces. It was said that M.2 only applies to the "form factor" of the SSD circuit board -- NOT the electrical interface. One needs a "small M.2 compatible slot" with PCIe x4 access (or something like that). And, as noted, even if the interface works, the motherboard has to be "built" to allow "boot" from the M.2 SSD. Otherwise, the SSD is just for storage independently of the boot-drive.

Like I said, I don't totally know the answer. I think, though, that from what I read, the latest motherboards have the correct interface and allow boot. So, I ordered one. Other folks may want to wait until their favorite motherboard is reviewed and they verify "boot".

If none of my favorite MB allow M.2 boot, there's another "hole in my foot" (would not be the first time I shot first and aimed afterwards)

By the way, it did matter that I ordered now -- and got the best price currently on line (only 11 left at that price). Apparently there can be a 1 or 2 month delay to get new stock.