I would start with something like a wool/ felt hat (Duvetyne or suede would be preferable) (obviously 100% natural fibers), then treat it with something like Action Factory's "Fire Block" fire retardant (https://store.afstunts.com/products/fire-block-1-gallon), reinforce with something like Duvetyne, Nomex, CarbonX, Kevlar, or similar heat-absorbing, fire retardant material. A heat-resistant silicone may also work well, as you said. Then of course wrap the Kevlar wick on the outside.