Standard shader vertex offset with compute shader

I want to render an object with the standard shader, but with vertex offsets (computed by a compute shader). Is there a way to extend the standard shader to achieve this kind of behavior, or would one have to rewrite it (the standard shader) to be able to pass compute buffers to it?

I'm pretty clear on the compute shader part. But not sure how to easily retain PBR behavior in a new material shader. So perhaps that is another way of expressing the question:

How do I keep PBR behavior in a custom shader?