Im not sure if its been already mentioned or requested, but I think a good idea would be to have a toggle for terrain on/off for those who want to create levels which are entirely indoors and have no terrain in them.
Or possibly have the option to only limit the terrain to certain specific zones within the level, so we don't have terrain polys millions of miles outside of the map where they aren't going to be seen ever/ever explored by the player. Imagine like a rectangle select and wherever in the map you would like terrain you could add it in that area... Of course you would still be able to have terrain across the whole map as well, but I am just thinking in terms of performance optimization.
Just an idea I had floating around in my head, not sure how feasible it would be now to integrate but I just thought I would share it.
