[Shader Mixer] Why is this a bad idea?

Oom Fooyat

I started to think about layered skins and came up with this.
It was a bit too easy and I expect it will jump up and bite me any at moment.
Before I start to get more seriously involved: Can anyone see a catch here?

The recipes is obviously not what was used in the render but it is the base for that shader.
There is a more readable version of the recipe here

Cheers! Oom

ReDave

Well, I wouldn't call it layered since it's more mixed than anything, but I can't see anything wrong with it, apart from the fact that two DAZ Default Material bricks will be slower than practically everything else.