Very impressive work dude!
A student from Digital Arts and Entertainment (in Kortrijk, Belgium) is developing a tool for UE4 to blend static meshes with the environment as his graduation project. With this tool he wants to remove the harsh seam that player sees when a static mesh intersects with a landscape actor.
It was 2016 GDC talk by Dice about Star Wars Battlefront, which presented in-engine tools to blend together natural meshes and the environment, that inspired the artist. In this presentation DICE showcased some in-engine tools to blend together natural meshes and the environment.
I currently have created three variants of this material. One automatically detects the landscape intersection, the second one uses a vertex-paint mask and the third one is a combination of the two.
You can follow the progress on the tool here.