Those heat wraps probably aren't made to get too wet. Not that I think it would hurt the wrap, but it's likely not in the design parameters. The amount of moisture that they see in their intended use, would be quickly dissipated by the exhaust heat. No idea though, whether it would hold moisture in your intended use.
But I would use insulation on the floor in addition to, or instead of. There's paint like coatings, likely ceramic, and there's asbestos substitutes, like rock wool. That ones for housing I think. But I know for a fact that there's automotive heat shield insulation out there. And likely there's something that'll be moisture, and drainage/evaporation friendly.
I would say to use a combination of things. Including carpet floor mat. Cut from scrap carpet. Ceramic tile under the floor mat, plywood, etc. Till you get what you need.
FWIW, I work in the carpet industry. And if I'm going to be on the forklift all day. I'll take 5minutes, and custom cut a carpet floor mat. That forklift gets hot. Carpet works well, and it's disposable. And since it's a brand new, clean mat. It's quite luxurious lol.