Blender notes, FWIW... In the internal (legacy) renderer, gamma is applied automatically within node groups. You can see what's going on by dropping an RGB input node in and having a look at the values vs. the color scale on the side. i.e. for 50% gray the values will be ~0.5^2.2. This also applies to textures, so if…
Ok, so been doing some tests on a variety of models with this shader to see how to deal with masks and textures. It's a bit tricky trying to reverse engineer it, so this is only my best guess at this stage. Right now it seems that masks do have gamma correction applied (default behavior in Blender). It also appears that…