Robo Recall optimization stream, mentioned, r.NormalCurvatureToRoughnessBias

Hey guys,
EXCELLENT stream, thank you!

You mentioned a console variable that i cannot find any documentation on:
r.NormalCurvatureToRoughnessBias

so, does this just work like , 0 = off, 1 = full affect etc…
and i assume this is a global setting, that affects the power setting that you set in each material for the composite normal?

Thanks!