I am skeptical of your first statement though. It needs 5 mols of oxygen for every mol of propane for 100% complete combustion. Incomplete combustion exists, and there is air surrounding the front of the GBB. I would NOT RECOMMEND PUTTING A MATCH OR LIGHTER IN FRONT OF YOUR GBB. This may or may not be able to stay below the flammability limits. 2-10% is the range. It may momentarily stay in this range, which could cause a flare. Not worth trying what so ever.
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