"This file was available for a limited period of time and has now been deleted. For more information please check our FAQ's." So, I can't download it.
Meanwhile, there's a few things I see wrong with this. For one, if your friend is the host and doesn't want to change it back, then the soc is useless, as he's the only one who can run. And besides, if the filesize is large, then it'll just mean people may not be able to download it upon joining; if they were, they'd downloading what was already in srb2.srb in the first place.
It's not a bad idea, and it's totally fine for Single Player, but I can bet anything that it won't come quite in handy in netgames as it would be expected to.