Sorry, you'll have to pay OOP for any appetizers or enhancements (sides) or extra beverages.
Looks like the breakfast entrees at the Grand Floridian Cafe are pretty combo-meal - by which I mean, they're complete meals and likely WAAAAAAAAAAAY more than a proper portion serving.
Not at all like so many other places where you feel you are building your own platter and half of it are items not covered by Dining Plan
Like this Lobster Benedict: "Two Poached Eggs, Toasted English Muffin, Butter-poached Lobster Tail, Hollandaise, and Marinated Tomato Salad"
So you have two main entrees
in a sandwich,
smothered in sauce, PLUS a salad. And if you order a specialty beverage like the smoothie as your beverage, you'll probably be satisfied!