Does anyone use a humidifier or teapot on their plain black F600? It doesn’t have a cooktop, per se, like some of the other Jotul models. There is an oval on top that looks like it could be a cooktop. The manual doesn’t specify. I just don’t want to do damage to the top by putting a teapot or humidifier on there. Has anyone done this or know if it’s okay to do?