While they may be identical in how they work and look, to me if it's on a chopper it's a kernel processor and if it's a stand alone piece of machinery it's a roller mill. The reason I keep them separate is to avoid confusion, as I know a lot of folks that run corn through a roller mill before packing it in a bunker.
Apparently this custom chopper doesn't know how to set his kp up properly, because when he has it on we get wet dust and when we don't use it the earlage turns out just fine. He probably has it set the way he does because he mainly chops for dairies and they want it finer than what we need.
If bunk management is good, digestion of the unprocessed earlage is just as good and intakes are better. If that wasn't the case we wouldn't be getting good digestion on the whole shell corn we use.