You should also consider increasing the batch size with your XU1. My standard roast volume is 300g but can easily double to 600g while still feeling in control of the roast. I find any less than 300g and the roast progresses too quickly and I am constantly trying to finesse the roast to perform as I desire. 300g is a good balance which allows me to easily roast quickly or slowly depending on what I am trying to achieve.
What are other HG roasters using per batch?