Mike..
Am no expart in this nor have i ever built anything or project yet, but am very much interested in what you have done. I wish that one day i could build a rocket stove like yours.
From the pictures you made, the first thing i noticed was that THE SECONDARY BURN(where the heat/fire travels Upward is TOO TALL. The heat generated is not able to cover the whole Burn hence not heating the whole room well.
I believe that if you manage to cut the BURN PIPE to a half and then cut the Insulator as same as you cut the Burn area will help the heat to travel faster and you will use less time and fuel for the same project.
Heat generated must be greater than the Secondary burn and the Outside Temperature, for it to heat and be Stored in the stove
Again it's just my opinion not from experience speaking.. please don get me wrong...
