I think we should have aircrafts and large terrain maps like in RoR. Maps like Grenoble, where you could just have fun with an almost infinite amount of space, should be in BeamNG too! Also, we should try to reintroduce aircrafts to the game. Flying through the crisp blue sky with a conglomeration of beautiful nature below me would be very fun to experience in this simulator! One last thing would be a day/night cycle.
Bigger maps could be built, and planes, cranes and all these machines are planned to get ingame already...
I'm sure that bigger maps are planned. The grid is seemingly infinite. Have you tried that? You can jump into the editor and change whatever you want in it.