From that page, in the Q and A section, I found this:
Q: can this stove be used indoors or on a sailboat
A: Manufacturers wall/ceiling clearance recommendations are as
follows. 1 foot on sides and 4 feet on the ceiling.
A: Instructions state outdoor use only but I have it in my cabin. Keep proper ventilation and clearances and there will be no problem. It is an open flame gas burning unit so CO will be produced and could be a problem with no fresh air in a closed room or cabin, but that is the same issue for any type of stove. Manufacturers also have to err on the side of excess caution because some folks don't put brains in gear when operating products.
............
For me, I'd probably not use it inside a van. I don't have a van yet but will own one soon. I'm not sure how I want to handle cooking. It is likely I'll just not cook at all. I don't want to have to carry propane in my van. I could see using this on a table outside the van but that would also mean I'd have to carry propane in the van. So... there are other things to eat besides cooked food.