There are no general rules except one: "there are no general rules"!
Also, I would disagree with that statement in A&T, as I have seen the great improvements possible with newer emulsions in spite of the difficulty encountered in making the emulsion, so there is maximum advantage on the part of the user and not the manufacturer.
Modern making equipment is very complex due to the nature of these emulsions and that is inconvenient for the manufacturer.
I assure you that if there is a new edition of FDC, and if I have anything to do with it, that statement will be changed and I will offer proof. If you want proof though just consider the difficulty of making a graded core shell emulsion to get high speed with small grains!
Thanks much for that reference. You can all see that Microdol X is nothing to be excited about! However, a lot can be done with developers and the Kodak family just about covers the gamut. IDK where you can find anything better, but I'm working on that! Others claim to get superb results with this or that home-made formula, but I have yet to see one of those compared exactly to the best of the best on that chart!