Maybe I need some coffee, I don’t see why you need to adjust anything.
I just tried that mode in my game and all the non power-of-2 GUI stuff is right.
If the UV is not in range (0,1) anymore and the (0.1) range will only cover your actual image pixels, that means only the needed part of the texture will cover your plane or whatever. Isn’t that what we want?
EDIT: OK, I just tried with egg-texture-cards, not my function and I see what you mean. I don’t understand.