Yes...remember...R&D does NOT mean Research and Development. It really means Rip-Off and Destroy
I'd make it with three legs and maybe just a little more leg splay. The legs would be short enough to slip down the chimney for storage.
Keep the leg socket ends under the 'dripline' of the top would keep it compact.
here's a refinement...since the wind is NEVER blowing in the right direction the unit could easily be mounted on a swivel base. Then, the draft is better and the smoke is going away.
There is some sort of 'badge of honor' earned from cooking with the smoke blowing in your face though!
Now I'm going to start looking for scrap materials to make one!
Tom