It's a proof of concept. The biggest roadblock in making a custom editor have always been the terrain editor. With this work, we have the opportunity to create the editor of our dreams, that wont rely on hacks or other sketchy methods to work. And as he's already showcasing now with his pathing palette tool, we can even add things the original editor couldn't do. In this case, you can change the pathing using a brush instead of pathing blocker doodads, and you can do it on a more detailed level that pathing blockers can.