Man, I would actually really love for this to gain some momentum so it becomes something that is a native part of the core engine code in Unreal. I cant go into any details, but thats how we do it. Its a core functionality and thus its also way cheaper so we can afford to do it cross platform @60 fps. I can also say that our solution automatically picks up the terrain texture, so there is no need for custom material instances depending on where you wanna place the asset, but again…its all handled natively via the engine code to make it fast and working in all cases.
I also think this is really something that will become more and more important to keep a high visual quality for games now and in the near future so PLS Epic…think about a native solution for this 
Cheers!