A skirt around the pot dramatically improves efficiency. Covered pots save fuel. Professor Grover ends his report by including a paragraph on pot design. I heartily agree with him that a new pot, designed to increase surface area to volume ratio, and that forces heat to rub against the pot surface would dramatically improve fuel economy. Effort spent in improving the pot as heat exchanger is many times more likely to improve cooking stove efficiency than improving the combustion side of the equation.
Complete combustion reduces exposure to harmful smoke.
All stoves should be designed to reduce such exposure. But complete combustion, in my opinion, does not greatly increase the overall efficiency of the improved cook stove.