This quest is just awful. The poor design is a jarring distraction from what is otherwise a pretty polished gameplay experience.
I tried to cross the chasm 5 times. Each time it was IMPOSSIBLE to tell when to move forward. I got knocked off before I even jumped down behind the wall. I would get knocked down even standing besides the wall.
I died and that was enough to teleport me to the waypoint only to die to the pressure plates which incidentally still trigger when you jump over them. The only way to prevent the damage was to dodge-roll over them which is completely unintuitive!
Terrible quest that needs to be fixed.