You can at any time use the procedural material as a sub texture in a classic setup with splat textures https://docs.unrealengine.com/latest/INT/Engine/Landscape/QuickStart/5/index.html and so to say apply some hand editing on top of it where you like to have something different in a particular location. For example below buildings if you are adding human build structures to the landscape.
The “horizontal Bands” are an intentional Effect that you can just blend out in the instance of the materiel.
