Quick update. I've made converted the plasma heightmap generation to work with on a sphere. I've set it up so it creates 4 textures, one per quadrant (as seen on the bottom of the screenshot). It's mapped in a wierd way that skews it a bit but it seems to look fine from space.

Bonus: In the edges you can see the patching at work. It's really easy to determing which patch to use, I can just test each edge and shift a bit up and add it to result and the final number is simply the index of the index buffer to use. (e.g. if edge 2 is at a lower level I just use index buffer 2, if 1 and 2 are lower I use buffer 3).