Quoted from shaub:
So, here is my "solution" for now. So far its helped but I could definitely see balls still getting past it. But time will tell.
The ball should come out of the "4-prong wire cage" under control and in a predictable direction (straight down) every time. The exit prongs are not set correctly. If it were my machine, I would take that wireform off (as well as the homemade plastic guide), place a ball in the "bird cage" and bend the prongs inward (by using a length of steel tubing or hollow punch with an I.D. that will just fit over the end of the wire prongs, or you could just use pliers) to minimize the clearance so that the ball is forced to slow down and exit under control and straight down. If you do that, I guarantee that you won't need the guide.
Edit: Also, it may just be the angle, but the 2 long prongs appear to be angled a bit toward each other. You want all 4 prongs to surround the ball equidistantly as it exits, so those 2 prongs may need to be bent outward away from each other a tiny bit.