This weekend, when I was home, I wound up tinkering with the overworld some more.
I now know what my issue was before, and it was as simple of a problem as I had figured it would be. With the Displacement Modifier, the texture being used for the displacement, one needs to make certain that the way the image used for the Displacement is set to clip instead of repeating under the Image Mapping section.
So now that is working, I am working on adding the props in via Blender instead of Unity. A test of the render in Unity after adding some props.
You can see the textures have been redone on these screens too. I am testing some much higher resolution textures, this should allow me to scale things in the Dungeons better so it does not feel like an itty bitty character in an improperly scaled environment. That work will come later, once I get more done with the overworld revision.
Of course the textures will be cleaned up, melded, merged and I am going to go with procedural generation.
H8, Start Screen:
L8 (Destructible Chunk):