Landscape (Material): efficient Mask Painting; what are unused Layers for?

  1. Basically vertex painting for the Terrain, I would like to paint certain parts of the terrain where I apply special Material functions. I suppose I could use a non weight blended layer for that, but are there steps to optimize it, or any better solutions?
  2. In some of my old Landscape Materials I found unused Layers for Alpha and Weight blend. I remember they had some sense but I can’t find information about it, does somebody recall why these were necessary and if they are still required?