It's not really the point of Troy Grady's work to copy anyone's style 100%, more just to analyse how they make it work, and the advantages to all of the different mechanics of each picking style.. with cool animations, that makes it easy to visualise. If you gets to the point where you own a Fractal product, you've probably already got a good foundation to work with. And as you said, different anatomy means that what works for one doesn't work for another. Grady starts off with downward pick slanting, and then two way pick slanting, but also string hopping, swiping, bouncing etc etc.. it can be interesting to see the advantages of each style, but it doesn't necessarily mean copying it.
It can even just help with making slight alterations for better efficiency, or for understanding picking mechanics as a whole. He branches out even further from there.. but yeah.. efficiency and mentally understanding what is going on can benefit anyone, regardless if they are playing MAB or even simpler pop stuff. More efficient, less mistakes, more chance to play for hours without fatigue etc etc. It's cool stuff, if you're into that kind of thing.. like documentaries etc. It has a Discovery channel vibe to it. I started off with Petrucci type stuff, so alternate picking is ingrained in my arms, I guess I'm an upward pick slanter, but his stuff has helped with tidying it up, making it more efficient.. and also encorporating some EJ/Ywngie type stuff.. in terms of fast pentatonic 2nps stuff, or economy picking.
One of the simplest things for me has been the idea of customising the picking for each pattern and knowing how it will make it easier. Instead of always being on automatic and being strictly alternate picking. I've always struggled with long fast runs, and I'm starting to improve with that, whether it be starting on an upstroke, or economy sweeping, or adding a pulloff or hammer on to make it easier to pick etc. It might sound like a simple thing but I really see the value in it now and can imagine over the years, things will get much easier, and this will become the new 'automatic'.
In terms of MAB, probably no one can copy his mechanics fully because he holds his arm and wrist in such a weird way. And it only really works for playing MAB stuff. But you can still become more efficient without needing your arm to look like his while you're picking. That's what Cracking the code helps with to me, because it sort of animates what is happening.. and that can be replicated.. or at least.. the advantages of a style of picking can be replicated in your own unique way.. it doesn't have to look the same, it just has to sound the same. Even when you choose not to do something a certain way, having learned about it, and understanding why you choose against it can be helpful. Instead of wondering if you are missing out on something.
It isn't covered much but something I've realised as I've tidied up my right hand mechanics in the last month or so, is that my left hand has been the weak link all along. In terms of speed, efficiency, accuracy and keeping it relaxed to avoid fatigue. Obviously when they are both strong, that's where the super speed and accuracy comes in.. and MAB is a freak at that, one of the best ever.