I have never rock-climbed, only briefly messed about enough to know it's not happening despite my pull-ups peaking with +50kg added weight.
The "not happening" was that my weight distribution feels like it was ripping me off the wall. I just can't get much percentage of my bodyweight supported by my toes because my big back, ass and quads are going in another direction. Turns into an upper body exercise and one-arm pull-ups on a sheer face aren't happening.