Sure, I've seen & helped with offset mods using pipe before: this one look like about 6" for a 20" diameter pit and thats not bad. It also it looks the right proportion (firebox looks about 1/3 of cook chamber). Looks like the biggest challenge will be heat loss the way that door works and he won't have the benefit of all that thermal energy stored in a heavy RF baffle plate. He will just need to learn to keep is closed up and get the fire right. Might also consider some kind of grease/moisture drain in the cook chamber - he does not want a pool of hot grease up against the fire box - it will ignite. Interesting build, I would like to know how it works out.