Juniors are some of the most aggressive, fearless drivers I’ve ever seen and so the most likely to run over someone’s tail in my opinion. If they learn in their first 8 years of driving that they can run in to the kart in front of them without consequence, I’m not sure that they won’t continue trying to do so despite the lack of bumper in senior. I opine that it’s all or nothing. Remove it from all of them or keep it for all of them. Or maybe keep it in Cadet, as those are just little kids who should be kept as safe as possible, and remove it from Junior on up.