That is an interesting idea! I have had the Disney computer do some fabulous magical pixie dust things to enhance my dining experience over the years though. I am always a solo diner on the Deluxe Dining Plan, and anyway, I often like to get two or maybe even 3 appetizers - like I am always a sucker for all those international cheese apps alot of places have and then I often want a soup and one other hot dish or something.
Well, anyway, quite a few times at the end of the meal, they have come back to tell me that after scanning my magic band, I didn't have to pay out of pocket for any of my extra appetizers at all, and they said it had nothing to do with them, it was just how it got processed.
I've never ordered 2 desserts but I wonder...if I did do that, I think there might be a good chance of that happening! And all the times I didn't have to pay for the extra apps, I didn't exclude anything else from my meal experience - I still got my beverage, entree and dessert. You might find that to happen for you, too, if you order an extra dessert, maybe not everywhere but who knows. I can't be the only person this pixie dust has happened to on the deluxe dining plan.