MuhVerisimilitude
Hero
There are a few skills were the upgrades are less obvious. Performance is one of them. In my prototype the first stage of performance is "proficiency with X" where X is an instrument, voice or performance tool. The second stage is a charm effect against a small fraction of the audience. The third stage is a mass-fascination type of effect.Not every skill works that way.
That's the problem.
Really only the Movement and Stealth skills have secondary measurements that you can have a second growth track outside of success.
This is where feat based games like 3e or PF2e struggles with.
What is the second track for Performance? You play at higher decibels?
Perception gets a few range related upgrades as you advance it.
But yes. It roughly functions like skill feats in PF2 except rather than being a distinct thing they are baked into the skill itself.