I built an insulated reverse flow cabinet smoker for my food truck a few years ago, and used a charcoal basket with one fair-sized split surrounded by charcoal on three sides to make kind of a consumable minion style maze, and I had virtually zero fire tending to do. Kept an eye on the temp, and occasionally adjusted the intake.
It produces plenty of smoke, and a nice smoke ring.
It used up the split and maybe 3/4 a bag of charcoal, in a 12 hour cook. Toward the end of the cook, I would have to sometimes collect the remaining coals into one pile, to keep the fire going, but that was about all the fire tending I did.
If I let the temp get to high, it took forever to bring it back down.
I have some pictures on my old laptop. If I can find the laptop, I’ll share the pics and what specs I can recall.
I used Lump for a while, but briquettes Burn utterly consistently, so eventually they won out.
I never tried running only wood, but I would have sacrificed the consistent burn rate if I had. I was the only one working the food truck, so I had to be able to lock everything up and leave to pick up supplies at Sam’s, periodically.
I don’t have any experience with GF, but if you can feed chunks of hardwood with the charcoal, it may do just fine.
Cutting up the splits into briquette-sizes chunks might get tedious.