Ok we all know about how you can super bounce through the wall to skip the first green key door right? well I was collecting some extra lives for green hill DD and I always bounce through the wall because it's more fun and all since picking the key up sucks.
I went to attempt it on one run, but I kinda mistimed the super bounce, but instead of having to do it over what happened was I bounced at around normal bounce ball height, but I shot right through the door itself(through the side of it I believe, hard to tell) landing a little bit past the checkpoint.(I had a lot of forward momentum, kinda like what it does when you bounce down a steep hill) it was probably extremely rare and tough to pull off, but it might be possible to replicate, and since I shot through the door itself and not the wall it might possible to do it on the second door as well, which obviously would be the one you'd want to do it on.
I wasn't taping at the time(sucks, coulda use slow motion to see when and where I bounced) and haven't been able to do it again so far, so if it's possible it'd probably be "harder'' to do than even cybrax's loop trick, but you'd save around 15-20 seconds on M1, probably 20-30 on M5