My second try to make more realistic moss material in Substance Designer. It is almost fully procedural except for initial input moss strands, which come from small atlas texture which I baked in Blender. I am still not satisfied with it. When I compare it with proper scans, it is still not there. I think I created something like grass/moss hybrid :D, but it is better than my first try and pretty well usable.
You can buy it HERE: https://www.artstation.com/a/155720
Or here on Gumroad: https://gumroad.com/skywalger#lSSPp