It depends on how complicated the screen setup is, and also if there are other geometry or resize commands in the code.
I am currently playing with the code from zuc.
If you have the cross compiler installed on a linux box, there is an editor included that allows you to drag the screen size out, and enlarge the icons etc.
It only took me 10 mins or so to sort out the zuc display, but there is more work required as some widgets are re-sized later in the code, and some text is placed on the screen later in the code, this text now appears in the wrong place.
I would hate to do it without the designer app, it would take hours.
Peter.