So, I'm not sure if it would look right.
But if your game window is set for like '1200 x null', Dunno but and the window takes up the entire screen it would be nice to be capable of manually altering this through the LU window mode.
I'm sure pixels might look funny, Maybe..
But there are other windowers out there that override GTA III's default window mode.
I know it would be possible, I could see the LU client browser having a force window size selection/Saving.