I'm not sure what you did with the tex coord from xyz because it's not immediately obvious from the render but no matter what you did, it's a nice terrain.
When you use more than one fractal for terrains you can't get coordinates from one to another to blend them with altitude because it will not know any altitude until it passes through the compute terrain. The tex coord from xyz will allow you to blend terrains via altitude before they go through the computer terrain after which you can then add all your surfaces as usual but the terrain can gain more interest before you start layering over your final surfaces. The more you can build in at an early stage, the better. It makes your scene simpler and more efficient to deal with.