Quick answer on a few questions here:
1) Sidewinder sitting all the way down in the cone - That is actually an approved configuration for esbit mode.....the first stake holes up are for alcohol.....top holes for wood burning.
2) Wood burning efficiency - All titanium cones (ULC/Sidewinder/Classic) are designed to support the pot all the way at the top of the cone in wood burning mode. This is for several reasons.....larger wood box.....opens it up for airflow.....and clears the handle cutout as a wood feed. Now, with the pot all the way outside the cone, the only surface area that "sees" the wood fire, is just the bottom of the pot. Consequently, the wider pots will always be more efficient in wood burning mode....narrower pots like those supported with the ULC will always be less efficient. As noted, efficiency may not be as important with wood because the fuel is so plentiful. Now....as to alcohol/esbit efficiency....
3) Alcohol/esbit efficiency - With the pot down inside the cone, the heat coming off the stove/esbit not only hits the bottom of the pot, but is held next to the sides of the pot very well....and you get really good heat transfer. So, wider pots have a larger bottom, but short sides.....taller pots smaller bottoms but larger side wall surface area. For full size cones, where the whole pot is down inside the cone, pot geometry doesn't make that much difference. The Sidewinder up on stakes in alcohol mode exposes very little of the pot to the outside and essentially all of the water is down inside the cone, so we haven't seen any difference with a sidewinder over a full cone. The ULC however, exposes so much of the pot outside and so little of it inside the cone, that it is less efficient in alcohol/esbit.....and much worse in severe weather (cold/wind) where it can really suck the heat out of the exposed pot.
Hope that helps!