Usually after you run the sample thru the dryer you have trouble finding the bits of cobs. As long as you're not getting docked just sell them. Having a few bits of cob is better than grinding up the corn, slowing down for the sieves or overloading and running corn over the back.
I guess it is more of a pride thing for me. I did close the concaves abit this morn, to help the rotor move the cobs out. The corn is running 15%, 200bpa+ green plants. I do have a cracked kernal here and there