I use a Mr Buddy MH9BX portable in the shop-8x12. But I can hang a sock and tell which way the winds blowing outside. I have the camper set up to use it as a back up to our permanently installed Wave 3.
But I've only carried once & used once. Likely pull the hose and rerout to use for outside BBQ, just a bit too much for us. (or possibly another Wave 3 to use free standing but havnet bought any lottery tickets latley). We have a bottle top cat heater for em backup.
The Mr Buddy does put out more moisture and it does get a bit fumy compared to the Wave. The Mr Buddy is not a catalytic heater.
The BIG is big.. fan nice but cant imagine the Big in a small TC.