RE: M4800 and Optimus?
I am in the same boat and would love an answer. I have been told that it is Intel's fault and a problem with the driver. I have also read elsewhere that it is just not possible with the QHD+ screen, but I am hoping it is something that a BIOS update could fix - for example, I know for a fact that Optimus is enabled on the M3800 (which also has the QHD+ screen).
I would also love to get an answer to whether or not a new BIOS is on the way.
On a side not, I had to roll back from A03 to A01 because after updating, my system was not able to wake up from sleep (I think this issue is specific to Win 8 or 8.1, but not sure).