ICVFX gamma encoding LED screen calibration

I’ve seen the quick start video on how to use OCIO with nDisplay, which is heavy on using PQ encoding. There is some brief mention of how Gamma encoding might be done, but no specifics.

At one point, it’s mentioned a value of 1.0 related to the peak brightness of the screen. What is the recommended way to “map” engine values to true screen brightness values in this case?