Time-independent lerping of Time.timeScale

I have a predicament. I want to "animate" `Time.timeScale`, but I want it to be framerate-independent. In my particular instance, I want it to count from 0 to 1, or 1 to 0, over a set amount of time. I obviously can't use `Time.deltaTime` or anything like that, since those are dependent on the time scale. And I can't just subtract it, because then it becomes non-framerate-independent, so it's either really slow in the editor, or really fast in builds.

So... how can I create an effective "Time Scale Lerp" that is framerate-independent?

You could grab your own delta time storing Time.realTimeSinceStartup and use that, should work well enough