It would change the dynamic of the cooker entirely. Instead of the heat venting up the double wall contruction, it would vent DIRECTLY into your pit. Which would also really mess up the "rolling" of your smoke. If you notice when you open your door and watch the smoke, it rolls through the racks, you wouldnt get that as well. You are also basically eliminating your water pan and going to a direct heat smoker. You would then have to turn your meat and the whole nine. I always keep mine closed, I set my hide when I go into the finish phase of the cook, I throw what I want finished into the top rack area, bring the pit up 15 degrees from wheever I was cooking, and let it crisp it up, I come out with a NICE competition bark that tastes awesome. Hope that helped.
What the frig is "gelled fuel" and why in the world do I need it at a competition?