I've been having more dispenser jams with the new design and the reason turn out to be the increased baffle angle. I made it steeper thinking it would make sure the peanuts would roll off of it onto the vibration platform. The side effect is more lateral force on the peanuts. Peanuts in the shell are relatively light (compared to shelled nuts) and have a rough, irregular exterior - even a little lateral force is enough to jam them up.

So I'll be going from ~30° incline back to a ~15° incline to fix this. Otherwise, everything is working well.

UPDATE

The angle of the baffle is somewhere between 20° and 30°, about the minimum for unshelled peanuts to reliably roll off of it so none get left behind. On the old baffle, there would be a few peanuts sitting on it once the hopper was "empty". Instead of reducing the angle I cut a couple square cm from it and raised it about one cm to leave more clearance for the nuts to pass by.

This seems to have fixed it - no more jams within the dispenser and quick, reliable dispensing of 1-2 nuts per dispense.

UPDATE 2

The angle of the feeder also matters. Since I simplified the mounting system, it is possible for the feeder to be mounted not quite vertical. In this case it was leaning a few degrees away from vertical making it more difficult for peanuts to reach the dispense opening. Adjusting this reduced the dispense time and increased reliability (no jams).