I ran a Mr. Buddy in my previous slide-in FWC Hawk. Catalytic heaters don't really produce carbon monoxide. But they do use up oxygen AND create a lot of interior moisture. With the "porous nature" of pop-up campers neither of these are a great problem. (It is good to crack a skylight.)Is there risk of CO poisoning with these?
What we didn't care for with the catalytic heaters is the lack of a thermostat. So you'll constantly be turning them on and off.