Re-implemented this a couple weeks back, seemed to run without issue...then over the past few days, it again caused a problem. Simply, an open 'MUD browser window would ping the server every 10 minutes to see if there were new Alerts. Enough users leave multiple windows open, and leave them open ALL the time, that those pings were overloading the available connections. We bumped that number from 10,000 to 30,000 and that alleviated the 503 errors (mostly), but even after 5 days, SOME of those browser windows are still pinging.
Developer has a new update pending, it's in Beta right now...will likely test with that when available. Ideally, it is added to the usergroup Preferences options and be offered to Supporting members.