I've run a round hole bottom sieve in a Gleaner.You can open up the top chaffer,so all the half split pods have lots of time (full length of chaffer) to fall down into shoe. Then lower round hole sieve will cleanup the grain going to the bin. Half split pods are returned to be rethreshed. The Gleaner has an opening so you can view the returns. When the beans are green (as in low ground) you see lots of returns,On the high hills you see NO returns. If I was to adjust to Thresh out all beans in low spots I would be OVERthreshing on high ground (causing split beans) This is one Disadvantage of the IH, Not being able to view the returns, To see if returns are half split pods,leaves, stems. Making the decision of turning up the Cylinder speed or Air speed more difficult Thats why the guy at the elevator said I had the cleanest beans,and PAID a premium for them.