Loving the editor and the game. I've managed to make and import some map models into the game, all is good there.

Is it possible to create custom overlays? If so, any tuts on this?

@joemama Yes it's possible. Depending on what you want to do. Road and path overlays can be made custom. I've never messed with cliffs or borders or power lines.

Got a link for a tutorial on this?

It would be great if the game makers shared a sample overlay (max file).