Hi TheJamsh,
Thanks for your reply. I’m not insisting on them being decals. If Epic could give us any better solution, it would be great.
You refer to curvature map in Ddo, Substance and such, but you gotta keep in mind that those will work on unique meshes with unique textures, which fit in 0-1 space. What we are talking about here is something like architecture, which is using tileable textures and this is one of the ways to add extra details and variety to them (e.g. you are not gonna have curvature map for skyscraper or castle 
)
As for them being expensive, I don’t believe they are more expensive than regular decal materials. It’s probably not ethical to mention other engine here, but take a look at Crysis or Crysis 2 assets. Those geometry decals are extremely common practice there and majority of meshes use them, yet performance is not that bad.
Would be great to hear from , of course. Maybe he can give us some super clever solution to our problem here
Just as an example of how these are extremely useful (I think I brought this example up before). You have to make a city road with markings. Using regular decals becomes a nightmare very quickly (imagine aligning solid road markings all over your map, we’re taliking days of work). But if I can use the fore mentioned technique, it’s as simple as slapping a thin plane with tileable texture and using vertex colors to create variations.
If needed, I can setup example scene to make more sense out of that.
BTW, if someone can implement this shader properly and put it on Marketplace, I’m getting it right away, though it should be there out of the box, since we have deffered decals already, they just fail to work with geometry.
And yes, I think you got the reference right 