/3/ - 3DCG

>>691576
Plot twist. Got it figured out (albeit really hacked together)
Seems you have to completely zero out the normal channel to overlay and replace another on top.

So I had to put my initial map down, add a fill layer that resets the normals to default, add a cloud mask to that so some of the old normals show through. Then duplicate the initial map, and use the inverse mask of the flattened normals to fill in the gaps.
Lather, rinse and repeat, switching up seeds for each pair.
Also, it doesn't work in groups for some reason :^)

Don't really know if it will help anyone, but figured I'd post the solution anyway. Seems like a really roundabout solution though.