Scott Mercer showed how some of that was used and performance provided a bonus up to 3000 SR.
The big take aways where SR is modified at <3000 SR by performance.
Decaying to 3000 meant you would get more SR for winning to quickly get back to where you had been. In addition, the closer you get to 5000 the less SR you gain per win compared to potentially lose.
Granted who knows how much of that is true anymore with the new role queue. My thought is a few things will be similar.