Mmm... I think I'll stick with Iwasaki's advice, the guy knew a thing or two about steel, edges, sharpening, etc.
This will depend on allot of factors. How much wear is there on the edge, what stones are you using. The quality of the steel might also factor in.Is the best practice to evaluate and determine if the 8 or 12k will remove the problem in recommended number of strokes while doing a touch up, or hone on the 8k until the problem taken care of, regardless of stroke count?
I’ll stick with personal experience versus advice.
This reminds me of when I was teaching guys how to operate a Sunnen Hone at work. When I would show them the stone cabinet and they always asked why there were so many different stones?It all comes down to trial and error. However, it doesn't hurt to invest some time to understand the technical aspects of the variables.