Mighty Mini 12 - 12 inch tiny woodburner

I think it would work great in a sauna

I think your first step would be getting a copy of their requirements for certification, and a list of their test procedures, so you're not wasting money trying to get certified until you're sure the product and your business conforms.

Second step, and perhaps a means to the first, is finding and calling some standards testing labs. I'd find out who other stove manufacturers have used (check tag on back of stove), but also try to find someone local.

I agree entirely, this is the route I would take.