If the question is about roasting on the Mini500, I had to stop due to the shells getting caught between the drum and faceplate, jamming the drivetrain. To alleviate the problem I backed the drum a bit to create a larger gap and increased RPM as it was set below 50. The close tolerances on the Mini, about the thickness of a business card are smaller than Cacao shells that inevitably break up in the drum.

I've got a used #6 RK drum to experiment with next.