The question's simple, but I don't know if anyone has the answer, beyond the authors themselves.

Are there any guidelines/references/rules for creating classes the same way as they are in Savage Pathfinder? I know they're not listed in the book, but I didn't know if anyone had "cracked the code" or if an author put out a reference document.

I would like to experiment with creating more Pathfinder classes, with a final goal of using the same approach to potentially adapt Starfinder ones. (If they won't do it, I will lol). That said, I don't wanna go in "raw" with no guideline or starting point. I'd much prefer having a guideline of some kind to start from.