When we check for # of licensed users, we pretty much load all active users into memory. This makes it SLOOOOOOW, and we do it every time we save or update a page.

It's not critical that the license-check is always or immediately performed, or that it updates in real-time with new users, just that it kicks in 'soon enough' to annoy people who are over their license limit. Thus we should perform the count in a background thread, pass all "are we licensed?" queries until we have a precise result, then cache the result for a while before we have to do the count again.