Most pros I know don’t go above 3k. There’s no point other than a hone. Anything above 3k is almost counterproductive and a waste of time. Unless of course your doing some seriously technical work like soft protein (sushi- and even most those guys don’t). At/above 8k you’re going backwards for a pro that does any kind of volume. All tooth is gone. And that tooth is why white is so good for pro kitchens imo. Perfect example- Marko 52100. At 3k it will chew threw your cutting board. At 8k it’s just not angry or toothy, it’s a tamed beast. But again I don’t know the science or really care, just real world observation here.