Caves on Tight Displacement

[WAS]

Was hoping I could find a solution here. I'm not sure what to do. Basically i have a voronoi shader making circles stretched on Y. They are supposed to create caves into the spires. However they only depress the displacement a tiny bit into the structure. In fact how the depressions don't seem to change at all when I up negative displacement, until the displacement is poking out the back side. It seems almost like lateral displacement can only achieve positive displacement away from itself and not inward in this instance.

So bizarre I can get peaks off the sides, but not peaks into the sides lol

[WAS]

Here is an example of caves only, you can see the depressions only go in a couple meters, but can protrude a lot farther. :\

[Dune]

Maybe the mask isn't 'white' enough? What if you multiply by a constant 5 or so? Or the displacement displaces the xyz out of reach of its own mask?