Outdoor Rocket Cooktop and Double-Boiler

I think this is a great design for an outdoor rocket cooktop and double boiler.  This would do great under a pergola, or some kind of cover, to protect the cob from the weather.  I love rocket stoves, but this is much more versatile and expands how much I can cook at the same time...it's like a grill with a burner only better!  It's much cheaper using small pieces of wood instead of propane.