I have been cooking mostly on a ProQ Excel 20. But, at the recent Arizona BBQ Festival competition, I won a custom-built "UDS". But she really is a "BDS" (beautiful drum smoker). I have seasoned it and worked on controllong the temperature, but I do have a question: On the Excel 20, and on WSMs, the top vent is supposed to stay open the entire time during the cook. Is it the same with a UDS, or is the temperature controlled using both top and bottom vents?