Quote - Well guess what. When I turn on GC, I get horrible dark skin like you did.

I added a simple white prop to show there is plenty of light.

I'll be back. I'm not sure that RM's shader works with GC at all. I got it to work fine in P8 with HSV Exponential tone mapping, but that's a totally different formula.

Do you see the white lines in the textures? That is from texture filtering. RM's shaders have it turned on. I'd have to go turn it off in all material zones, or use a lower minimum shading rate (MSR). Low MSR costs more time. PPro is already unbearably slow for me. If I lower the MSR to get rid of those lines, I'm going to burst with impatience.

I can't believe how much I managed to learn with such a slow program.

I always get  these white lines with lower render settings (draft) but they disapear with higher settings.
As you say, it looks to me like they mark the limits between the different parts you find in the MAT room (ie: skin torso/skin arm)