Just wanted to provide a small correction. You have this inverted.
I talk about this in the video series. In programming, you a boolean has a true or false value, which the computer reads respectively as 1 and 0. When we are plugging textures into material nodes, it is looking at the same equation of 0 being false (glossy) and 1 being true (rough). When you create a linear texture, glossy will be black and rough will be white.
Also, OneMinus will only work correctly if sRGB has been turned off. However, if the texture hasn’t been generated properly for Linear space, it isn’t going to look “correct” when it is imported.