Well, I read on the GC dev forums a while back that one of them was experimenting with a giant space map. It could contain their biggest existing space map (which was huge, not to mention empty) in a single 1942 "gridbox"
As for some older posts here: You can set teh Bf2 player ammount to whatever you like. But performance issues will appear for sure. Size change is very bad idea since all objects would have to be scaled down in 3ds and terrain model is based on grid with limited number of polys. So if you would have small units something like causeway, ditch or ground pile would be a mountain/enoroums hole or soft, big hill/shallow big hole.