Landscape mesh blending - accessing layer info possible?

I’m trying to build a system for smooth landscape & mesh blending. I do get nice results by combining world aligned textures plus pixel depth offset. But I wonder how I’d automate the selection of the texture to use for the blending with a landscape that has multiple layers applied? At the moment I’m using manual vertex painting (attached screen) but I’d love to have a fully automated setup. Anyone got any ideas?