My approach to heating the van has evolved over the six years I’ve lived in it. My use case hasn’t changed: I follow mild weather and only rarely/accidentally get caught in hard freezes. Dipping slightly below freezing at night is about the limit of my tolerance.
Each winter brings a flurry (ha!) of first-timers wondering how to keep warm. Not giving advice in the above post, but explaining how I do it.
I boondock in the desert southwest with vicously dry air and have constant ventilation -- the buddy doesn't push the hygrometer reading up at all. I imagine it'd be different in Florida or something...
My stove and Buddy have never caused the CO meter to go above 0ppm. Other things have but not those.
Will be putting an espar in as soon as I can find the time and motivation to install it.
If I won the lottery I'd use something plumbed into whatever the camper's fuel tank holds. I had a 1973 VW van in [the former West] Germany that had a gas heater. That heater was epic!