A: Adjust via whatever “gauge” method you prefer to get close. Then use trial and error. Roll a small test strip. If it rolls out straight, you’re fine. If it curves to one side, tighten the side it curves to,by one tooth on the adjustment gear, and try again. Repeat till it’s as close as you can get. The test is more sensitive with thinner metal, and with less annealed metal, which stresses the rolls more, showing up deflection effects.

There are limits to this, simply because you can only adjust within the steps of one whole tooth tighter or looser on a side. And if the rolls aren’t perfectly flat, or the bearings are unevenly worn so that the mill curves the metal in one portion of the rolls, only on one side, but not in the middle or the other side, then you can only get to some close approximation and you’ll need to find the best compromise.