We don't have balls on our cranes here, collars instead where the cable is socketed inside to the upper part of the hook affair and held for the most part by a self tightening wedge. I suggested to a crane op that does a lot of tree work that he have a steel ring welded on the side of the collar that you could put your rope through. It would eliminate the uncomfortable feeling when limbs are pushing through the hook where the rope is. He seemed to think that it was a very dumb idea, I guess in part because you can't modify a collar and pass inspection. I dropped the subject when he almost became hostile. I still think it's not a bad idea if certification or some other means of acceptance could be implemented and safety guaranteed. The collar does bang around on wood sometimes, maybe something attached on the side or wherever is problematical.
Running the rope through a steel ring put through the hook and lightly laced to the neck for added security is how some guys like to roll, especially if wire rope choker is attached to the hook at the same time. No getting your rope buggered up with the choker when pulling the standing end through.