I think your problem mainly stems from missing out half of the nodes I told you to use...
I'll have a look and see if I can get it to work.
I'll upload a tgd if I can.
EDIT: Ok, I've got something, the hard thing is telling whether the scale is actually increasing based on altitude or not.
The other problem is that there is no conceivable way of increasing the displacement as the altitude increases.
EDIT2: Ok, I think we have success!
As you can clearly see from the image, the voronoi sharply increases in scale at the top of the slope.
Now what you have to do is epic tweakage to make it look right.
good luck!