I'm using Principled Shader VOP inside VEX Material Builder for Karma CPU because I'm using some custom VEX shaders.
I've met an issu that Emission of Principled Shader VOP didn't reflect any color.

This workaround is to connect Principled Shader VOP to Compute Lighting VOP.
This shadergraph could drive the emission.

Why did I have to append Compute Lighting VOP?
I guess this is a bug.