This. I’m aware that this wasn’t possible before either, but I was kind of hoping that it would be now. Create a library of material instances (grass, wood, stone, dirt, metal etc.) and sometimes blend them in different combinations, but sometimes just drag & drop one of them directly onto a mesh.Right now you can’t drag & drop a layer onto a mesh, because it’s a material function, not a material.
So you’d have to have each of your materials twice in the project: once as a layer, and once as a material instance. Any possibility that it will change?