Hi,

It's more of a compatibility with Skylake processors than the board itself.

If hiluke said it works with his ASRock Z170 board and Skylake processor, then I'd say that is a safe recommendation.

Yes, the Storage Support lists are not maintained as good as they could be.

IMO, an Incompatibility list would be more useful for a Storage "Support" type list

At this point of PC development there should be no compatibility issues with any SATA HDDs or SATA SSDs.

M.2 SSDs can be SATA, PCIe AHCI, and PCIe NVMe.

M.2 SATA SSDs should be no problem unless the manufacture did something non-standard with the M.2 key pattern for the drive.

M.2 PCIe SSDs should also be fine as long as the manufacture has the M.2 key pattern correct. For NVMe SSDs, NVMe support listed in the specs or in a UEFI/BIOS update, is the true indication of compatibility.

If an M.2 SSD is not classified as SATA or NVMe, then it should be PCIe AHCI.

I've used M.2 PCIe SSDs in ASRock Z97, X99, and Z170 boards as OS drives without any difficulty.

I've used the U.2 to M.2 adapter for the U.2 variant of the Intel 750 PCIe NVMe SSD with  ASRock X99 and Z170 boards, and it worked fine, and is bootable.