Was happy to find a glide that saved around 10 seconds, then while looking for the last secret I found this jump which skips almost straight to the exit. That secret actually still confuses me as I have no idea how to open that door from the other side.

I use my first grenade on 2 imps which can block your jump and the second on the chaingunner. The jump is pretty precise but didn't take me too long to get it in a run. Am sure this one can still go a lot lower with a quicker jump.