Not to sure about the drum fire, with a low charge weight perhaps it gets the job done quicker. I kind of like the idea of seasoning the roaster with coffee oil rather than soot. I intended to just roast a couple of dark batches in ours before trying the coffee, but lost control of the first couple of roasts anyway!
Yeah, I think I'm gonna give the fire a miss! I'd be interested to hear from anyone who's tried it though! I have read about it somewhere but can't remember where at the moment and I think the idea was that the fire got rid of all/any debris/muck from the drum and the previous seasoning and allowed for a new seasoning. My first couple of roasts ran away to and the first one certainly was not far from fire and that was after about 8 minutes! Steep, steep learning curve!