What I found was that if you crouch you can stand further out on a ledge than if standing ( about 2-3 pixels I would guess). so if you find that spot, release down and fast press up+attack (without touching left / right, that would cause you to move horizontally) it took some time to find out how to release it after repelling down, but just holding up+left and spam attack seem to most of the time cause him to drop down.

I was messing around in Sagila's cave and found another way to get through it without doing the snail jump. I'm not sure if its a better route and my guess is that this would be counted as a wrong warp as I transition between screens in a non intended way. So before investigating if it's something that could be used in a run I wanted to check if it would be counted as a wrong warp.