@Jeremy-Ross Oh wow you've really put in the work! Well done. I'm glad that I learned about master copies from 3PP, I think it nets people almost immediate substantial improvements, depending on their initial foundations.
I've only been doing parts of the original artwork as values only rather than the full artwork, just to try and understand the general technique. Once I feel satisfied that I've figured out that I can replicate the general technique, I then document the process of brushes, layers, adjustments, so I can refer back to it later, as I'm constantly reshuffling my core brushes around.
I think I'll eventually create a user manual for myself to follow, as I sometimes forget important shortcuts and steps.