AFAIK as long as you don't blow cover or violate the course description (tac sequence/tac priority) you would be fine to re-engage.
Ok. So it works likea dis?
1. Tactical priority. Once you get the initial sequence done in correct order you can go back and pick up a miss or misses if you want.
2. Tactical sequence. Once you move to the next target you have blown cover on any target not neutralized, so trying to pickup a miss on an early target is going to be a procedural regardless of where you are when you go after it again.