I am thinking about closing off the upper of the two air intake butterfly openings on my Oklahoma Joe Longhorn Smoker/Grill to improve its airflow pattern and possibly efficiency. Has anyone done this already and can provide me with their insight, or does anyone have any thoughts on this. Here is what my OK Joe looks like: Here is the view from the outside of the butterfly air intake (2 openings that can be adjusted from wide open as shown here, to fully closed, and in between): Here is where the placement of the two butterfly openings are relative to my Charcoal Basket, which sits directly atop the original OK Joe Charcoal Grate, and immediately under the original OK Joe Direct Searing Food Grate (there is an Ash Drawer underneath which is a very convenient feature): I am considering removing the movable butterfly plate visible above and welding a piece of sheet metal across its upper opening, and then re-installing it so that I would only have an adjustable lower butterfly opening. I am thinking of doing this because at times I have seen smoke coming out of the upper opening, and the upper opening seems to be poorly placed relative to the fuel load. I use this Smoker/Grill for Smoking in the Indirect Heated Food Chamber, as well as for Direct-Sear Grilling on the Food Grate in the Side-Burner Firebox (see the placement of this Food Grate above). Can anyone point out any Pros/Cons to the upper butterfly opening before I make this modification? Thanks in advance for any guidance!