No need to apply the fix. Just tap twice on the monkey icon and everything will be ok (corresponds exactly to the landscape = 2 manipulation described here above). Even if you do it manually, ScummVM will be remember that setting for next time - you can configure that setting for every Scumm game and for ScummVM itself. With landscape = 1, the touch response does not work correctly. With landscape = 2, the touch response works properly. No way to centralize the screen though.
Regarding WVGA compatibility, from what I understand there will be no such compatibility. This does not have to do with ScummVM but rather with the games which run on the Scumm engine. In particular the older ones run on non-wide screen resolutions. Consequently, any WVGA scaling would result in stretching the images, unless you wanted to get rid of the ScummVM menu bar during the game. That would require reprogramming the interface with context menus to replace that menu bar.