I'm 6'6" with an arm span of 6'11" and currently play with a 63 inch cue. Im looking to add a rear extension to do exactly what your asking as right now my grip further back feels more comfortable but my stroke gets wavy when I do this as the cue feels lighter the further back I grip. I'm hoping the little extra behind my hand acts like a rudder and helps me maintain a smoother and steady stroke.