Most trailers use high density foam for cushion and in many cases, bed mattresses. High density foam, even when new, is not the best material to sit or sleep on as it compresses a great deal. I have cut pool noodles which I place behind the seat back cushions to slope their angle. It improves comfort, but it is still not as comfortable as a quality couch, because high density foam will never be as supportive as the furniture in your home. I would suggest improving the upholstered seats of the dinette. You may be able to find custom cushion makers on line who do not utilize 100% foam in their construction techniques.
And if you haven’t yet done so, you might want to join the
Escape Owners Forum where there are likely more owners than on FGRV who have dealt with the “comfort” issue which is concerning you.