Besides the decreased surface area and lubricant retention for friction, a textured surface (by whatever method) would retain oil for rust prevention....
Just for me, I'd back up and look at the original bolt picture or another example of a jeweled bolt. There are surfaces that I see that would benefit more from rust prevention than are typically covered.
I could see where reducing the surface area might decrease friction, but I'd think the high points were already well fitted and the dips done in a controlled manner. Less surface area to me would mean quicker wear, and the texturing never seems to be on the surfaces that're designed to bear.
I have seen instructions that generally comment about friction reduction and retaining lube, but then warn about keeping the abrasives away from lugs, cams, sears, pivots, etc. These are only thoughts, maybe I'm biased because I don't care for the appearance overall.
