Make yourself some thick filler bars for concave. The thicker the bars the less aggresive concave will be. We've had guys fill the hole concave in with thick fillers and or install plate over top of concave for sunflowers. Don't know if your dockage is that out of line but you can likely do better. We have had most of the trouble when heads and stocks are wet and small wet chuncks of MOG needs to be seperated from good seeds. Filling every other slot in concave may help you plenty. The other trick we have is rotor sweeps. I only have sweeps made up for P3 systems but St. Johns Welding has enclosed rotor systems for P1s with a rotor sweep setup. let us know how you get along.