Valve train geometry

The roller tips put no appreciable side on the stems; that is the point of using them. Centering the pattern does not change the side loading at all. So don't worry over that.

And not being centered is not of concern as long as they are not too far off center. The thinking that being perfectly centered is the best geometry is dead wrong. What you care about is the scrub pattern being narrow. Measure the width of the scrub pattern; even with the best possible setup, you won't get it much narrower than .035" with around .500" lift.