Ron, Looking at the current layouts for the 2910, I think they have discontinued the dinette in the slide option. It says the it now only comes with two slideouts. They must be listenning to your concerns about the side of the dinette in the slideout.
What I had to say would apply to most models where a slideout has only a dinette within.If I were considering a used PC and it happened to have one of these, I would not let it be a show stopping issue. I simply would try as is. If I could not live with it as anticipated, then do a little home remodeling, modifying the interior of the slideout to "Plan B".....whatever plan B is for you. Just make sure you have a plan B before the purchase.