While speedrunning this level earlier I accidently found two spots to clip out of bounds, not sure what's ahppening but I believe it may have something to do with boosting into the doors at a certain angle but that's just my best guess.
Nice ! The first one happend to me too and i tried to replicate it to see if i could get to the end like that, i was able to replicate it but couldnt reach the end... The second one seems even harder to do lol, slowing the footage , it does look like it was about the angle of the boost to the door, and also maybe because of the corner right next to it . My best bet for is to find some other door in some other corner next to the bound of the level AND close enough to the exit, and we may have found finally a new clip to save a lot of time !!
I wasn't able to replicate after seeing the footage of what happened myself but I'll try to mess around with it a little more, but yeah I do have a strong feeling that it has something to do with the boosting into the doors at a certain angle, and you may be right about one of the requirements for this strat is the door being really close to a corner as well, out of all the times I've seen this happen I believe that it's always occurred with a door in a corner and for clipping in this level maybe it's just me but I feel like you die faster in this area, maybe the kill zone is closer and that makes it harder to use this efficiently and if we can decipher how this happens we could potentially save time on every level with a strat like this!
