There shouldn't be any problems as long as you are in UEFI mode. Confirmed from engineering. Now if you are having issues, can you be really specific about the issue, also screen shots would be helpful as well.
What slot(s) have you tried? Also, when it is plugged in, is the drive detected in BIOS? It should show in the top where other PCIE devices are shown, as well as how many lanes are being used for the SSD.