OK, Thanks. I see. It didn't work quite right the first time I hooked it up because I hadn't changed the fake stones shader's colour so it was not influencing the colour from the power fractal so much.
These experiments can still yield other results though even when not a best solution for the first problem. You can use final normal in the first layer then terrain normal in the second but use the first layer to generate different colours or textures from another power fractal shader hooked into the fake stones. Blending still works but you get more subtle colour variation.
You have to bear in mind that coming from Mojoworld these sorts of masking things are difficult so I don't expect easy solutions already built in
