The miscommunication there is likely my fault. I probably just thought it was how it was supposed to work and didn’t dig too deep.
It wasn’t the intended initial design by our lead designer. The main problem with the breakpoints like that is it has exponential increasing returns with higher and higher investment. As the increased effectiveness goes up the damage it deals goes up and interval goes down so they multiply with each other. The rate that the returns increase at is increasing.
In general we tend to avoid increasing returns but increasing increasing returns is a problem.