How to recreate world machine landscape in unreal?

This has had me stumped for days. I’m looking to:

  • Create a new landscape based on a raw heightmap (done)
  • Import image representations to drive where each material texture should be painted.
  • Allow manual landscape painting for cleanup.

How can I create a proper landscape blend which imports the painted data from masks but also allows for manual painting? None of the documentation seems to cover this. I’m able to make blended weight-based landscapes which allow painting or height-blended based landscapes for two textures which don’t seem to allow painting. I’d like to have say 5-6 possible textures, each with their own maps, and each with the ability to paint.