I would like to have some kind of TAG string that we could set inside a material for each texture that we have inside that material. And also a way to retrive this TAG, probably on a trace hit result.
If you look at the attached pic, you can see that I have a mesh with a vertex painted material. With this TAG thing, I could query the hit result and know the texture name under the hit, with only one material.
The way Ue4 works right now, using surface types, for the same mesh, I would have to use two materials.