I imagine you may burn the reflectix lid as the occasional flame does shoot out the side when it is windy. As you mentioned the inner of the refectix is just like bubble wrap, so not too flame resistant. A foil lid works for boiling and will allow you to bend and store it inside the Caldera.The cozy would work well though, You could invert it and use it to hold your caldera setup together inside the trapper. AntiGravity Gear, who you can order the Caldera through can probably make you one up. I looked at customising one I had, but the result was pretty bulky, plus I don't have a need to keep my water hot for that long.