Stacking the JSRF bonus on top of the per-discipline one is a neat way to reward well-rounded builds, but yeah, needing a clarification post on your own bonus math is usually the tell that it needs a second pass - I'd probably fold JSRF into the discipline bonus itself rather than track two numbers per roll.
Viewing post in BONUS CLARIFICATION [EN/ES] comments
Yes, you’re absolutely right. It’s a sign that it isn’t written clearly enough. I had a look and couldn’t find a good place to clarify it, so the least I can do is rewrite the text of the first pages. Even though I don’t have much time, what I’d really like to do is make a second edition, get rid of the 3d20 rolls, and simplify everything; make it cleaner and more elegant.
I’d also like to support the player with drawings of different skateparks and more illustrations of the tricks for newcomers. That would be ideal :)