The movable pole pieces on a humbucker are designed to screw in and out so that you can balance the string-to-string response of the pickup, which can be an worthwhile adjustment.
We’ve heard people advocate turning the pole piecess so that the slots in the screws make a pattern, such as /// or ///, for the best sound. In the interest of being politically correct, we’ll say, give it a try. If your ears hear a difference, cool. If not, c’est la vie.
To be fair, some techs have use the alignment of the slots as a way to adjust the heights of the pole pieces to follow the curvature of a guitar’s fingerboard. Depending on the radias of the fretboard this may or may not work. We prefer to measure/eyeball, and above all, use our ears to adjust pole piece height.