To follow up on my own ' ball leaving the wireform ' post above, the issue with mine seems to be down to small divots in the rail made by the spot welding machine clamping too tightly. Every joint on both of my wireforms has these divots/depressions in the rail, but one in particular on the left wireform had a little bump on the edge of it causing the ball to start bouncing with a really fast ball, eventually bouncing off the wireform on the 2nd bend. I filed the little bump down and fingers crossed the ball seems to run a lot more smoothly and hasn't left the wireform in the last dozen games.
divots (resized).jpg