It would be great....if someone would offer a high(er) efficiency furnace for an RV. Auxiliary heat ( electric, catalytic, etc.) is fine in warm ( above 25 to 30) camping, but forced air is needed to heat underbelly and basement areas, when cold. It’s considerably worse if you do “cold” ( near zero or colder) boondocking....where battery consumption rates are high.
Kinda makes me think of the expression,”If you build it...they will come!” I know that I’d be interested in a high(er) efficiency, retro heater for our unit!