For your note on different states for screens. Can you elaborate or give an example? I'm quite interested in this mode that you're describing.
The ellipse issue sounds like snapping getting in the way. It's on my list to come up with a better heuristic of when to apply snapping or not. One example of an idea I have here is to incorporate some hysteresis effect - essentially examining the local history of mouse movements when deciding to apply snapping or not. Right now each mouse movement is treated independently.
Also, were you in dark mode? It's definitely not intended that the whole screen should change color - a popup should dim the content behind. The whole screen changing color sounds like a bug and I'll investigate.