Altered Time - your #1 World of Warcraft Mage resource!

So if we come out of burn with 2-3 stacks of AM, do we dump them after evocation? Or do we just AB to four charges and eat whatever missile procs come up in that period of time? The latter feels weird to me. Some clarification would be awesome. I'm losin my mind over missiles! EDIT: just re-read tha...