Well i'm sleep deprived and missing steps apparently. What i should have been doing is putting a matching BOM Top / Bot texture in my material for this to work, but of course it breaks everything else as there is now no way to tell the material what is emissive and what is not! Nevermind this post~

I was attempting to make a PBR skin with emissive portions who's brightness and colors could be customized using a simple BOM layer as i've done previously with Blinn-phong materials but it seems like neither the brightness or color transfer over into the Emissive channel leaving you stuck with the color you initially had the PBR Material's channel. This is quite inconvenient as it prevents us from using simple tintable and stackable BOM layers to customize emissive color and brightness. i've attached a screenshot of what this would have looked like on blinn-phong

See below for screenshots of the behavior.