I wouldn’t set the screws to be correct in the middle of the knob range. If you really load down the back you may not have enough range to cover things.
There really is no reasonable way to lift the rear beyond regular empty ride height, so the more solid strategy for most would be to set height via the screws with the knob on 0 or even 1 out of 5, then as you load the rear you have the full range of knob adjustment to compensate. Advantage with 1 over 0 is the ability to get a little more reach by going to 0 if you are driving at high speed on open road.. it flirts with being too much for oncoming traffic but that extra reach can really help.
Over the years with my suspension work I now drive around at 1.5 usually, going to 2 or 2.5 when loaded for a trip. I plan to change rear springs eventually and will dial in the screws as needed at that point.