Ok, maybe I can help some.. This is definitely the same design as mine, the Reverse Flow Flop thread that u read, with the addition of a warming box.. The very first thing uneed to do is cut in additional dampers on the firebox. I suggest one high centered in the firebox across from the opening to the cook chamber. If that doesnt work, cut some in low on the backside of the firebox. If your rib box doesnt have a damper in it, install one. My fear is ur rib box opening is disrupting the air flow. Instead of it moving in the cc and out through the exhaust, its stalling into the warming box. The main thing though is to increase your intake dampers. Im sure if u are trying to heat everything up to temps, ur fire goes out. Open ur firebox door and the fire starts burning again. This is a telltell sign u need more intake. Another thing I found with my cooker is, dont trust the thermometer on the lid!! Put one inside stuck thru an apple or potato so its not touching the metal racks. Your cooker may be hotter than u think it is! Basically adding a bigger exhaust and more intake fixed mine to the point its usable and very efficient. My plans are to redo my firebox so its a little shorter, wider and longer to better feed the cooker. Hope this helps, and let me know if u need any more suggestions!!