I should have been clearer. I like the canteen cup style, that is, nesting the pot in the stove/windscreen. The stoves themselves are heavy and generally inefficient.

Here is my plan for the next long weekend.
I will use the same titanium pot and wing stove, the same amount of fuel (whatever brand of hexamine is on sale), the same conditions (my garage), water from the fridge (same temp), etc. The change will be different shapes and configurations of stove/windscreen to see what works best. I will try to fabricate the sidewalls of heavy aluminum foil. This is to tes tthe concept and shape. Eventually I will get appropriately sized titanium pots to make a durable version of the stove.

Variables
1. no windscreen, wing stove only
2. replicate more or less the Caldera
3. windscreen to the top of the pot but not snug to the pot (the Caldera appears snug)
4. windscreen halfway up the side of the pot
5. windscreen to the bottom of the pot (see if the hot air is funnelled straight up with any efficiency)
6. then try bottom ventilation options

Maybe you could try the same and we could compare notes.

I anticpate the caldera is the most efficient, but if even the half way up the pot works almost as well, it would be preferable for me and my desire for simplicity (laziness).