We have a couple of smaller bins, 24'x6 rings and they don't ahve spreaders in them because they couldn't keep up with a 10 inch auger so we took them out.  Anyway, early in bean harvest if there are butter beans or a few green pods they will slide down the pile of beans in the bin and end up at the sidewall.  Luckily we hauled this bin out first and found them molding and and starting to rot because all of the wet stuff ended up at the sidewall.

I would really worry about this in a larger bin if I didn't use a spreader.   Spreaders in a big bin might not spread perfectly level, but at least it will spread any trash evenly and keep it from ending up at the sidewall. 

maybe I worry too much.