You are right - users with tiny screen resolution are in trouble in CAM 3.1, but I hope that this is not so relevant as working with graphics in our-days with 768 pixels in height is not in fashion anyway.
And maybe there is a solution for that size problem, @mrmister. If there is very big need to change zero point, then - yes - it is ridiculous - you can rotate your picture in screen 90 degrees left or right, then you get extra ~300 pixels to height, if you have wide screen. Change your zero point and rotate screen back.
Just thinking out of box...