I have also found that when I make my final adjusment, I close 2 vents all the way, and use just one to regulate air flow. This way I'm not playing with 3 vents at a time.
2 OTG One red one black
22 1/2" black Bar-B-Kettle with rotisserie ring
Brinkman dual zone charcoal grill
Webber Silver Genises B
3 burner camp stove