Okay this was brought up a long time ago in the Github issues. There are some alternatives already in the works. It might be time for me to upgrade my game to 4.3...
shinI'm going to go insane crazy style... GB Studio doesn't actually have diagonal collision for actors? In the collision code, they just walk around things in the Y direction and then the X direction. Collision in the diagonal direction is never checked. Thousands of hours and I never noticed...