Michael, first of all thanks for brain gym with this essay.

Personally I do not think that a lot of improvement happened in the hone world of the last 50 years. You can find barber hones and you can find historic recipes to produce hones that are similar to nowadays' japanese water hones in a lot of aspects. Whether its binder or grain, there are only so many possibilities to make a hone and to sift the material.
What is actually new, is a contemporary style. Shapton Glass hones for example. IMO they are a genuine life style kind of product.

Steel is still the same different and whatever you hone it with doesn't really matter as long as the progression fits.