I could be daft wrong, but I think I've found unused paths in the S2 terrain.pack, which potentially means unused maps. Which means I want to add them. If you're familiar with 3d collision, you might help me. See my question about that, here.

Maybe you'll see what I mean, when you compare the contents of the land_normals files with the pic I took of the template_map.xml - the rivers, hills, and forests files are unused!