All of my products ship via UPS Next Day because they are perishable. However, the speed at which an order is fulfilled has two categories: Standard (1 day for processing) or Expedited (processed immediately). I'd like to have a Standard rate with no added fee and an Expedited rate with an added fee. Is it possible to use calculated carrier shipping rates with two different tiers in the same zone? I've seen some suggestions on how to do this with manually entered shipping rates but not carrier calculated rates.