OVERKILL decided whether objects were equal by rounding each number to the tolerance. With 0.01 tolerance, circles at 80.001 and 80.003 merge, but circles at 50.004 and 50.006 both stay. It happens at the default 1e-6 too, and more often at the coarser tolerances people use to clean up imported drawings. The PR spells out the cost: a duplicate circle left behind gets cut twice on a laser or plasma cutter. The fix compares the numbers directly.