I've always wondered why I had so much trouble with this shader not doing much, or switching from "on/off" with settings. I think I figured out why. Most my scenes incorporate lateral detail, and when you use a Texture Coordinates shader, it breaks the Intersect Underlying feature. I wonder what other features may be affected in some way providing wrong results or not working altogether.
Yes, it can be used to 'fix displacements in place'. I use it to fix stretched fake stones before adding more fake stones that need to be stretched in other ways, or when adding smaller displacements for (fake) vegetation and later needing to smooth part of that for a path or so. Very handy shader.
Yeah but the issue is intersect underlying is broken when a texture coordinates is in the tree. Which explains why in testing scenes where I wanted to use it, it never worked, or suddenly worked, because it was the Texture Coordinates being enabled/disabled in testing.
I'm not sure why a texture coordinates would just rid the pipeline of displacement data needed for the intersect underlying. Seems like a bug.