Sounds like a good plan FF1. I've seen several folks at jet flyins doing just that with a booster battery for start on kero systems. Funny that the booster batt approach still leaves you with an extra piece of flight-line gear (the booster vs the propane can) .. I'd say 90+% of folks just use larger batts onboard, but for a 44-size plan this would be a great tradeoff.

Dave