Last Month the Japanese try to retrive this mod a little bit more. They played in the at 2pm CET. At the moment the gametracker,com Server Monitorring is off. Hope soon they turn it on. The ranking seems to work.
The buildings and vehicles are part of the mod, so the only space taken up is the entries of where they are to be location, spawn time, strength etc.
If the textures are done in Battlecraft, then the textures are tiles of the same texture, and so compress into small files.
If however the map textures are done in ED42, then its like a large picture, it makes the map look more releastic because there is no 'tile' effect, and lots of detail can be put in. The down size is that the information is unique and does not compress well.
In fact, the reason that battlecraft maps are smaller than ed42 maps (correct me if I'm wrong here) is down to the file type of the textures. BC saves as dxt3 and ED42 saves as dxt5. The tile effect has nothing to do with it. I say that because I have made maps in ED42 before then changed and saved in BC and the file size shrunk dramatically (with no loss to actual texture detail.) BC is more friendly for noobs which is why it has those settings to keep file sizes down. ED42 is good for Pro's (lol) who can take care of the compression and optimising in the final stages.
I reckon.... I have never really investigated it. didn't you show some method of opening, copying and saving ed42 maps with BC to reduce size? I forget exactly how.... when Camber sands first came out I think it was a lot bigger... suddenly Iwas working on it (after having used BC for some reason) and it shrunk like the Titanic.... still couldnt tell you the exact way it happened though