As the SH44 isn't insulated and the metal is thin, hitting a temp is conditioned on the weather. There are times when I turn one knob to high, push it in then keep turning towards "off" to achieve a low flame and 225ish temp. In colder/windier weather, I might run one burner on low, or two burners between "off" and "high". One of the great things about propane smokers like the SH44 is that it doesn't take long to dial in the temp. If it's too high, open the door to vent the chamber and turn the dial down a bit. Shouldn't take more than a few minutes to hit the temp you want.
One thing to also remember is that the chamber temp will be greatly affected by the amount of meat/thermal mass that you put in it. If you get it locked in at 225ish and then throw 10 cold 12lbs Boston Butts in it, the chamber temp is going to drop a lot and will take forever to climb back up to 225. Even throwing 1 butt on will affect the chamber temp, you if you want to smoke at 225, you should preheat to a higher temp. Also, as the internal temp of the meat rises, the chamber temp will rise as well. If you want to maintain a steady 225, then part way through the smoke, you'll need to adjust the flame down just a bit.
Personally, I'm not that much of a stickler for exact temps. I strongly believe in "ISH", as in, 225ISH, or 250ISH, or 275ish, etc.
BTW, should also mention that I don't use the chip trays, but rather, an
AMNTS smoke generation tube, which has almost zero effect on the chamber temp.