@corvathranoob It would be nice if buildings had zero volume until about 25% completion. They would only start to grow after 25%.
While it had no volume, if any unit was standing on it, you couldn't build it. If an enemy unit was standing on it, it would lose health (and of course it wouldn't stop an enemy from walking through it or dropping from a transport onto it). That would make it much harder to block an ACU or a drop (blocking a drop of course is not legal, but that doesn't mean we shouldn't fix it. It's better to take away a cheat than just to punish people for doing it.)