Dan,
I may not understand what you are suggesting. The ball is held in clamp by a thru bolt. If I don't clamp it firmly, then the ball can turn on the bolt, but in one direction/plane. At least in my use, the ball is normally clamped, so a larger thru hole will not help. Some ball links seem to work for a while with clamped and multiplane pivoting occurs around the ball by the nylon. Some seemed to work and later tightened, thus this thread for a solution. Most of my applications need pivot in one direction and work well when converted with brass tubing, but your description of clevis type action may be correct. There is minimal slop between the tubes and that will allow a minor bit of out of plane articulation such as at the flap horn from the bellcrank.
Again, Paul's article is referenced as it is his solution. I had some of the smaller, standard 4-40 ball links and used the same method, just a different stack of tubing.
Fred