not to jump on your case and all, but to jump on your case if i may, to say there shouldn't be any slack in the rope sounds a little like a perfect world situation. my experience with simulclimbing is the follower can't always go through moves at precicely the same speed as the leader (and often may move ahead creating a little slack to give the leader enough rope for his moves). so i think a little slack could easily be in the system, although hopefully not more than 20 feet or say at most i guess. anyway, a falling body speeds up pretty quick so can't even 10 feet generate a descent yank? i have a tibloc and it pretty damn pointy looking. anybody else?
You have a valid point. There likely would some slack, but I would hope not more than a couple feet. I suppose it could be as much as 10 ft. If you set a Tibloc, you know the second has some hard moves coming up. I would imagine you could make an extra effort to make sure no slack develops until he is past the move.