Not exactly a breakthrough, but a slightly larger dispense hole will make a big difference. 22mm is small enough for some larger peanuts to jam in if they hit it wrong, It then takes a while for them to get shaken out of the way or finally through the hole. This jamming is the main culprit behind my occasional slow dispense times.

I'm going to elongate the dispense hole by~50mm towards the center of the jar lid. This should prevent jams from larger peanuts and improve dispense time and consistency without affecting dispense quatity much. I usually get one peanut now, and may get 2-3 more often after this modification. I plan to do this in the next day or so.

On the side I've started prototyping a simpler version of the dispenser assembly that is adjustable to accomodate shelled and unshelled peanuts. Hopefully in the next couple of weeks.