I think to make the progression more interesting, some moves for fighting styles should be scaleable.
Example: For yakkadori it should be scaleable in the sense of damage and size, however it wont just be based off doriki, you have to train it through usage, and as you use it, it will slowly become stronger and larger.
And you could also do this for other fs moves, but it also makes op moves way more interesting to progress.
For example, if some strong character's move is added, like mihawks, you shouldnt just get to use a slash the size of a mountain off rip when you complete the quest. It would go just like yakkadori prog, more usage = stronger, better move.
I hope some other parts of progression are also improved, its way more interesting and fun to have stuf like this in.