A RAM graph may have been opf some help; or perhaps not... It may have been useful in helping diagnose the issue but as RAM usage fluctuates so radically it may not have given you much indication at all (unless you were watching the Hub at teh busiest time for all your sites).

So I still think that your request is a good one, but the Hub is not intended as a full blown monitoring solution. If you are running production stuff that people rely on, then setting up some sort of proper monitoring solution is probably the way to go...