Absolute mouse "works" in any situation. You are responsible for reporting the physical and logical min/max values for the mouse. The host translates these into screen coordinates.
So if you report the max x/y as 32767, and the current x/y as 32767, the host will translate it to the corner, regardless of size of screen.
So if you report the max x/y as 32767, and the current x/y as 32767, the host will translate it to the corner, regardless of size of screen.