I am using ball links but I am not using the phenolic control horns. I picked up some uni-directional carbon fiber from Aerospace Composites and cut out all new horns. They are extremely stiff and I have had no problems. The other thing you could do is set up the Impacts controls like the scale aerobatics guys do. They order a second set of control horns and mount them side by side with a gap between them big enough to get the ball link between them.