hey, I just tried this and it works beautifully. There's a single annoyance though, and its that by adding the toggle to settings.php manually, I change the ownership of the file and then I have to leave it world-writeable or Vanilla won't be able to save any setting changes. This could be confusing, and it's a bit cumbersome. Plus, one could easily forget about the toggle, so my request is:

could the extension get an application setting? or a pref somewhere?
thanks :D