They can only use a certain size of terrain, they can't make anothing outside of the existing terrain area that's in the map. Also that would be impossible for anyone to run the map at all.
I am not a guru when it comes to Torque3D, but I believe that the engine dosen´t support much bigger terrains anyway. also given the fact that Italy is already kinda hard to run even on good systems, it dosen´t make sense to make it like an 8x8km map.
Pressing F11 opens up editor that is used to make maps, open that, then start copying existing buildings on land that has not buildings, it is very soon that you will find out something interesting, but in theory anyone can build more on any of the maps, in theory that is
the biggest map is Tennessee, that requires a mid to high end rig to run on much more than low settings, beam devs have to appeal to larger audience so official maps are smaller to run on more systems
A good idea for there would to copy that other island of terrain, and make another Italian based map on it, then you could have two Italy maps that coincide with each other
All the while I'm wondering how amazing your pc apparently is to think Italy was wasted potential... I can't wait until I get something good enough.
I think he meant that empty landmass as wasted potential as he probably wanted to drive there too, not that Italy would of been completely wasted potential, just that decorative island next to Italy. Have you tested that map after 0.15 update? I haven't personally tested, but I have heard it runs now much better. It has always been quite light to run in terms of GPU usage.
The mountains are there to provide a backdrop. The map has to end somewhere, otherwise you could keep saying "it could have been bigger" until the end of time.
People always will say that it could of been bigger. Then they load up Tennessee map and complain about shaking of their car because map is so big. Next thing will be that BeamNG must swap engine to this https://unigine.com/products/engine/unbounded-world as it uses double instead of float for coordinates, that gets rid of shaking