For us the dinette could be much narrower since we travel alone most of the time. And on rare occasions when traveling with others, they could eat at the driver/passenger seats, or we could set the rear lounge like a large dinette as in the 25.5 floorplan. Basically it's just about making the design more modular so it can be used in more ways.
Picture below is of a used motorhome in Houston showing how spacious the kitchen/dinette area can be without having to go to a slide by simply using a 2-person dinette. Even if Thor wanted to keep the dinette wide enough for four adults, it could be made the width of the bathroom or a little less. A width of 38~39 inches may be a good compromise.
On previous post it can be seen that even a full-width dinette sticks less into aisle that table in front of sofa.
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