I've only used MM for one heroic SL and I didn't do any setup... just moused over in order of importance. It did seem to me that there might be a great way of marking that may or may not be supported. Does MM "remark" as I mouse over? Lets just say I have a two pull with tank and off-tank and I mouse over them in the wrong order (start with the off-tank target). I assume MM will mark the first one with Skull. Now, when I mouse over the second target (that should have the skull since it is higher priority), will MM switch the old one to X (or whatever the second tank target is)? It would be great if it did that, either automatically, or if you could just have one key to "reassign all marked targets" at the end of marking the pull.
It does that automatically. Wave your mouse (in any order) over a pack of mobs a few times and it will change marks accordingly. One swipe is usually not enough...in BT I usually have to do 3 swipes (back-forth-back) to get all mobs done properly.