Can you give me an example of this? My current system only accepts gold nuggets; it's the simple hopper sorting system. Everything that isn't a gold nugget gets refunded as well. At the ninth gold nugget, a redstone pulse blocks one of the hoppers from accepting anything, including nuggets, so those get funneled into the refund system as well.
I am unsure if I have enough extra space to do this. For now, I just redesigned my system to use a dropper instead that is connected to an auto-dispense circuit set at a very slow speed. Hopefully it'll work!