I’ve seen a couple people using them at BKC already, it seems a good idea. They got into a crash and instead of the bumper breaking the mount got displaced and it could pop right back into place. Granted, this works in smaller collisions, maybe not bigger ones, and is just a small side benefit but still interesting from what I saw.
Route 66 is following suit and from the race I ran they need it. I started last both days, one for swapping a carb and one from a DNF, but I made 6 positions through just staying on the track. It was a mess and I thought they were going to throw the red flag after one crash right in front of me.
Final thing is that I was talking to Jamie from Franklin Kart the other day, and he told us that at the X30 final in France, their junior driver Maks Kowalski came in at least 50% of the time with his bumper down because in the starts he may get run into, but following too close to the driver ahead of him meant he got his knocked out of place too.
I like the idea and am planning on getting some before the season starts this year to get used to it in case I am doing anything wrong that may cause the bumper to drop.