:) I'm really glad to see you put the mod to good use! Amazing work on the video, it really looks fantastic.
Unfortunately following items on belts like they do in the trailer isn't possible without some fairly ugly hacks that only kindof work. I would absolutely love to add that functionality to this mod though, so I'll keep an eye on any api changes that might make it possible. For now, the best way to do that would be to just make static waypoints from one point to another and try to sync up the camera speed to fake it.
For your train suggestion I will look into how it might work, if it's not too complicated to implement I think could be a nice addition to the mod :)