Yeah, sweet, thanks Eddie. That's pretty much what I did on my test boil. Stuffed around with it a bit to see what it'd do but in the end, left it open.
I've had to play around with the air intake plate depending on how the pressure is set on the regulator to prevent the flame from popping and going out. There is no seal on and the plate doesn't fit snugly on my burner. The casting where the plate fits onto the burner is slightly asymmetrical on mine. Does the job though.