You can likely be waited on after 10 minutes. You need to sit nearer the main buffet area. If you sit farther away from where the food is, the longer it takes for someone to walk around.
As to your other comment, while not the same, find the snacks you like before the buffet closes and take them back to your room, then have your snack whenever you want after the buffet closes. We will sometimes grab items we like and save them for later.