. Rolling with a screwdriver is more often used on maple necks with a finish. You need to use a smooth chrome Philips cylinder shaft, held at 45 deg by both hands, and scrub back and forth compressing the wood and finish. You are breaking the edge so it's no longer sharp, as if the guitar were played for a career on stage. You can sand the other unfinished fretboard materials. You'll see much more improvement on Squire necks because they are carved from the leading edge of the fretboard back. MIM/MIA will often have flat fretboard edges and start carving behind the glue line. This leaves more wood on the rear shoulders even though the width and depth specs of Squier vs MIM/MIA are nearly the same. .