Yes DT gets priority, we have a score board and a total experience time target that we have to meet. We have the same ones for front counter but DT is given priority because there is a sensor that measures the total time taken from when the customer orders at the COD (the screen you see) and from when they are given their order. This times places us on the scoreboard, it is a constant competition nationally and something we focus on daily.
As a PP stated it is more of a "assemble to order" we have 3 different types of meat and they are cooked in small batches and are put in trays for 20 minutes with a timer and then discarded. As you order it comes up on a screen in the kitchen and it gets made on the spot.
As for the new frappes and smoothies.... The syrup is a blend of fresh fruit that gets delivered twice a week with the rest of our stock. We have what is called a BIM (blended ice machine) and we hook the bags of syrup up, it's transferred into the blender and then yoghurt and crushed ice is added to it.