New to site but there seems to be a problem fine controlling temps with the stock knob.
From my metal casting days, I've always used an adjustable propane regulator as I've required flow rates that were more than a fixed grill regulator could provide.
On my new smoker, I mounted an adjustable regulator on my propane tank and adjusted it to provide a normal flame on the "low " setting of the stock temp control knob. When the stock knob adjustment is used it functions as a "stock" smoker. Light and bring you're temperature close to your target temp and then use the adjustable regulator to fine tune temp from there. The gas flow remains stable as the gas level changes and will hold a constant temp until the gas runs out.
To start the burner I set it on "low" with the adjustable regulator flowing at zero and gas valve on. I hold a flame next to the burner and turned the regulator adjustment until it "hisses" and lights. I further adjust the regulator knob to get a normal low level flame at the "stock" knob setting of low.
Operate as above. Remember where the main gas shut-off valve on the tank is, if needed. Understand the process of adjusting gas flames and have a lit ignition source burning next to the burner when starting. The button start igniters are nice but if they fail to work you've got a potential gas bomb. Wear any safety equipment you think you need and don't sue me if something goes wrong, I'm not worth anything . . .
I grabbed this page as an example of adjustable propane regulators -
The regulator I use is old and discontinued.
Happy smoking - Kevin