I was at the AGCO plant the other day for a plant tour and product roll-out program. They talked about this problem as on-going with their new models that have the larger fan. A spokesman said they are working on the problem and it is JOB 1.
They could perforate panel under header clutch shaft. This would help but I think ultimately they need more square inches of screen to such threw. I would lower down screen door 2 to 3" and then extend the screened material under clean grain and tailings augers. This would greatly reduce suction per square inch thus likely never get suched up tight with material.