Are you getting pieces of cob in the corn or is it just not whole cobbing it out the discharge? We have a CDF in our 62 and its setup the same as yours with the addition of 6 sweeps, 3 of which are extended into the discharge along with extended helicals into the discharge and a lowered discharge floor.  We only run 2 reverse bars, out on the discharge end, just for a final tumble to release any trapped grain. Have thought about doing the F2 bar, but have been very happy with it so far and Im almost afraid to change anything up lol 

We get cobs in about 3 pieces out the discharge, but I think alot of cob breakup is the fine cut chopper we have.