In our 1995 PW, in order to use the beds as couches for reading, etc., I had a foam shop cut 2 identical , wedge shaped, foam slabs 24"x24"x12"x 6" and covered them with Sunbrella fabric (outdoor umbrella fabric, water resistant, wipe clean,etc.). One of these at the end of each bed, gives us the "angle" to support our backs as we sit. It feels like sitting on a "chaise lounge". We add another smaller pillow for further personal adjustments.
Stacked on top of each other, they form a "cube" which stores in the centre/aisle area under our king size bed at night.
We also use them together as a "cube" when we are set up outside on a patio rug. The "cube" becomes a footstool...or extra seating...or even a " table" for books and papers. (I put 2 small "self stick velcro dots" on each wedge so they stay together when "cubed")
You could make the wedges whatever size was most comfortable according to your upper body height. We went for 24" because my DH and I are both tall folks ..6'3" & 5'9"...and we travel in our "B"...for months at a time!
Have to admit that we do get some wry smiles from fellow rvers as they watch us "emerge" or should I say "unfold ourselves"? from our "B"!
We actually downsized from a "C" several years ago and love the freedom and flexibility of our "B".