RobynsVeil - you're welcome.  sorry, i should speak more nicely and smoothly.  i'm just not very eloquent at the moment.  it sounds like you're doing cool work, and learning tons.  good luck with it!

IDonn0 -  if she's using matmatic, not VSS, then she's using some other skin shader than the default one in VSSb2.  it's faking SSS, but i don't know how.  that means it's probably light specific.  iirc, the simple shader from the RDNA thread just uses the diffuse node.  also iirc, bagginsbill in a thread discussing skin shaders with face_off, showed that using just the diffuse node produced completely inaccurate results in certain lighting conditions, and those conditions were why face_off used his more generally accurate solution that actually used light position in its equations.  by explicitly accounting for light position, it was actually more light independent as a technique, though light dependent as a specific material.

lots of vendors are as thoughtful.  in fact most are nowadays.  they produce what bagginsbill calls "naive" skin shaders that don't produce accurate results, or if they do, it's only in a few lighting conditions.  they didn't mean to make light specific shaders, and they probably don't even know they have.  so they've done a whole lot of work making skin shaders that suck eggs in a lot of  lighting conditions.  personally, i messed with skin shaders a lot myself (for months, that was mostly what i was doing), and had significantly different results in different lights, though i wasn't explicitly using the lights in any calculations.  

you don't need to purposefully make a shader light specific.  when producing lighting effects, you mostly have to work at making them not lighting specific.

personally, i just want good diffuse, bump, displacement (yes, both) and specular maps.  i've had to wipe most of shaders provided with the characters i've bought so i could use my adjustment of the one included with VSSb2. conversely, i believe i have no more than two characters who've come with a specularity map. i have zero who have maps that can do regular skin and hands and feet well.