Just an FYI concerning the fact that MU works best when the user doesn't know it's happening.
There's an additional tool now -
User Punishment by BOP5 - which can be set to add x seconds page load delay, and these can be set to x*infraction points. I make it a point to tell people that their infraction point gives them a 4 second delay until expiration. It's not the random thing like MU, and there's no need to keep it secret like MU.
I still find MU useful for immediately cooling off hotheads. But that's just meant to give staff time to discuss an infraction.