>> Good theory, but I suspect the amount of energy input via the mag block would be small.
I agree. But it does perhaps double the surface area of the whole fuel tube apparatus. Maybe it reduces ice formation on the outside of the fuel line????
>> The canister would do just fine imho. After all, upright stoves do work in 'warm' weather'.
Ahh, but in an upright canister, the thermal mass of the liquid fuel remaining in the canister buffers the cooling effect. In a liquid-feed setup, the cooling would be dramatic in the fuel line until the temperature became too low for the fuel to completely vaporize upstream of the pre-heat tube. Also, in an upright setup, the canister itself can absorb heat from the environment, while the Xtreme canister is insulated by the black platic thingies from the fuel line (and preheat tube) where the evaporation takes place.
>> But the whole fuel line and burner have heat capacity, and would warm the fuel far better, and once the flame is there, who needs any other heat source?
We agree again. Hence, you can operate a conventional canister upside down. But, does it light easily and reliably? Can it simmer without sputtering out? The Coleman stove is designed for liquid feed and mass-market use. So perhaps it has these extra design details, that while not necessary for our Winter snow melting task, make it more user-friendly for the mass market.
BTW, Roger, as an engineer, I've really enjoyed your writings on bpl and your Aussi site. Thank you for your comments on this forum! Being able to have an exchange like this with someone of your credentials (or Ryan's for that matter) is one of the best things about BPL.