Totallymaxed: can't comment on whether the display drivers were working correctly (no way to tell really!), all I can say is that the exact same laptop, with the exact same PXE configuration stuck in a reboot loop before I tried to add the MD to the Admin console - (1audio: I note that it was well into Linux boot, having already done several pages of logging on the screen, including changing the font, so there is no indication of a PXE issue, it gets well past the PXE part).
As soon as I created the MD manually (as a device, directly, not using the specific Add MD function, as that didn't work as already described) and rebooted the laptop again, it worked perfectly.
Nothing to fix here for me, I was only testing using it, I am not attempting to get it working permanently, and have now moved on to testing other stuff - just thought it might be of use to someone else.