1.You may need to set a different value of Udc to change maximum speed of fan.
2.You need to hand tune P.I.D.
3.press button of ">" and hold a few seconds, you will find F-C option, click ">" a few times, you will find "Udc". set its value and press ">" again and hold till back to normal display
4.press button of ">" and hold even long time after "F-C", you will find P, I ,D, change their values, press again ">" and hold till normal display.
5. Indeed its a trial and error process. Different smokers will have different PID and Udc.
Every users need to find by himself.