Bah!
Well I supose that makes sense as otherwise cheating might be a bit easy
In this case it would be done for design purposes and all active players would be in the same position. But I could see a scenario where it could be abused
If I can hide the map file though I can still sort of hide some of what I want which would be good. As I can add many of the changes on to new sites which although the players could see they would not know where they are set. So even people studying the mod would not know if the site was in a neutral location, by someones start or even unplaced (as a very rare unique).
And I can always request the players don't study the mod's changes