on a little bit on a tangent but possibly related - I suffered alot of airballs on ghostbusters and through research and theory I determined that new targets stand almost 90 degrees to the playfield where 90's targets learn forward approx 5 degrees so roughly 85 degrees to the playfield. The rivet also on GB sits lower so in combination of the angle and the rivet it then when hit leans back beyond 90 degrees and allows the ball to hit and launch up. I redesigned the gb target base and introduced a 5 degree lean as well as reduced the mounting holes 2mm which effectively lifts the rivet 2mm higher and has greatly reduced airballs for me and a few others that have tried my bracket mod.

hope it at least helps in viewing the issue from another angle