I’ve been told by the people who maintain those machines that the cue ball is slightly smaller than the rest of the balls which allows it to move past a gate.
Not to try to hijack, but I think it’s a “cue ball”, not a “queue ball”. I print a handbook for a pool league every year and there’s been a lot of discussion on how to spell it, but I’ve never found a definitive answer.
Una (and by extension Khadaji) for the win, magnetic and oversized cue* balls.
CMC fnord!
*The ball is struck with the cue, which I’ve never seen spelled any other way, making it the cue ball. The only queue I’ve ever seen is the waiting list for a good table!