I don’t think it’s movement. I’ve defeated the interlock and left the door open and didn’t move it. Fired in one spot, shifted to precision for that spot, then tried another part of the bed and it had a different offset.
The camera lens calibration didn’t go that smoothly, first corners got good scores, rear ones struggled to ever get below 1.0. So that might be better. But even with the highest res camera, the pixel width is a limiting factor for placement accuracy on larger beds.