I have wondered about the use of knots in the rope to slow the rate of falling. If you have to prussik out, how do you deal with the knots? You'd have to take the prussiks off and retie then around each knot.
If hauling with a z-pulley, they would make the job more difficult. In the video in which Barter fell in, he mentions that his buddies pulled him out as he bridged using his feet and axe. On a team of 4, I imagine that one could put one guy to work as a belayer using the hip belay while the other two heaved. The knots would not be a problem with a hip belay.