ORIGINAL: pscartozzi
I don't believe it will work because the HL smoker puts out little if any smoke below 6V. At slow-med speed and at idle you will have no smoke. When you are wide open you will have smoke. I could be wrong.
Could you leave the heating element hooked up to the full battery voltage, and use a drive channel to power the pump motor? I'd think the response of the motor should be more proportional than the heater. If overloading the HL board was an issue, perhaps using a pair of diodes and a FET to isolate the actual power feed would work. This might even work with a fan providing the airflow.
D.