I would like a full screen PT but think of the lag that would create. It may just be that with the current system they can't resize the screen due to some kind of fixed things or values. Dunno, lol.
It's a operating system thing...how about we have three .exe's in the folder, one for regular and one for 2x.
The third is a launcher which you click to choose either one, you can choose the second one (it tells you if your resolution isn't big enough). Alternatively, we can choose the first two exe's manually.