The zooming was done by LiTTleDRAgo in his separate version; it hasn't been put into the official version. I'm not sure if I want to either. VXA's engine allows resizing of the window along with resizing the graphics. Essentially, you can make your game resolution 320x240, make the game window 640x480, and you have a pseudo 200% zoom of your game. Or you can resize the window to the monitor's size, remove the window borders, and *boom* pseudo fullscreen.
XP's engine does not do that, so it would require more work to get it to the same level as it already is in XPA.