Quote - I can see the difference, but I dunno if there's an easy fix. maybe displacement .001 or .01 or something. normals forward etc.

It doesn't really look like a displacement or normals problem.  Otherwise those would show
up in the unshadowed version too.
Try enabling texture filtering in your render settings. Everybody says to turn it off,
but that's because it is a resource hog.
But some hair actually looks better with it on if you are willing to spend the extra rendering
time.  And you say you are a perfectionist and do want a better looking image.