I keep mine nearly closed. Well mostly. Electric smokers have limited smoke and the more open the vent the faster its gone. Yes you can reload, but only so many times until you have to open the door and dump the tray. An electric smoker is about leaving the door closed opposed to a fire burner which constantly loses smoke and requires moisture renewal because of it. The electric does not require these.
Yes you can modify your electric basically trying to make it a fire burner so they smoke similar, but electrics and fire burners are different smoking types using different smoking operations. Even Jeff here agrees that with time and temp the ability of meats to retain smoke diminishes past 140 degrees. So what you see is usually a 2 to 4 hour smoke window for optimum smoke absorption.
I am not saying my way is any more right than Mules, and I acknowledge he knows smoking, I am only saying there is an ongoing discussion as to what is the right way to use the electric's smoking abilities.
I say, you should try it both ways and draw your own conclusion.
Again, no disrespect meant to Mule, just different approaches.