I've always kept the burner in the kettle, usually filled & often stored for months at a time, in turn stored inside the pans. Never had any problems with contamination but the burner is double bagged. One bag sealed round the burner & a second with that bag plus matches but just twisted closed. The top above the twist goes between the kettle & lid & then fold over under the handle laid on top. The layers of plastic bag stop any rattling when it is all packed away.
Although many is the Trange owner who pops the screw-cap on a hot / lit burner, forgetting it differs from the simmer-ring in that it has a rubber O ring... I certainly number amongst them 