For those using the propane/butane canister type, don't forget the safety issues--non sealing of the "valve" on the canister. At our L Powell gathering, one of the members noted that he had a leaking canister, and was able to "blow out the fire". I mention my friend who had 30% body surface area, 3rd degree burn, renal failure, coma for over a month from one of the leaking canisters which set things afire!
The first thing the paramedic asked during the medical incident at Lake Powell was "where is the propane?"….The patient had a high C O Carbon monoxide) level. Although propane/butane, is cleaner than some other fuels, there still is a risk--especially with a poorly adjusted burner.
Yes, we carry a propane single burner back up for the Wallas (not Wallace). The canisters are kept in the lazarette which drains overboard.