Correction for the salesman from Redline. A SWB can have a double burner and grill, it’s just the company he represents WONT fit a double burner and grill in a SWB.
We've not heard of that... but surely some ingenious person has somewhere. I gather the earliest Westfalia campers - very early 6os I think- turned front bench seats into bunk beds for kids. (Back of seat hinged up to form the top "bunk" while base formed lower one). Not sure modern seats could do that safely.... unless anyone knows different !