It is still a prototype, and the first fire is tonight. The bricks are cut, the floor is basic, and the chimney is a hack.
Here is the strategy.
Roaring fire below, and a charcoal fire on top of the 20" cast iron ‘dome’. This should negate the need for immense amounts of insulation used in most builds.
No mortar, so I can break it down.
Perforated copper reverse chimney so I can blow air directly into the fire.
I should have result photos tonight.