I did find a way but it affects other settings so this isn't really a good solution. What you send of doing is disabling "NVIDIA Tegra 3" from the Display adapater dropdown. From there the screen will reboot and you will be left with Microsoft Basic Display Adapter. You will see you have 4 tiles on the metro ui. The performance is awful since the basic video has 256 MB, whereas the Tegra has around 763MB.
You can easily enable the "NVIDIA Tegra 3" back from the device manager for it to reboot the screen and go back to normal.
I believe the reason this works:
How to get four rows of tiles on your Surface RT | JG's Tech Thoughts
-> is because you are preventing the surface won't "reading" what kind of display you have. So you will see the 4 tiles on boot, but the moment you put it on standby it will jump back to 3 tiles.
-> So it seems the default Mobile PC Display" is what is causing it to be optimized for the surface. Not sure if there is a way around it.
So you could make a batch file to disable and re-enable if you wanted to..Web browsing and youtube seems okay. Probably depending on the codec used, video application is very slow, and some apps probably too.