You won't get overrides for whatever area you are in. For example, if you are in futurescape and you make one you will never get a futurescape override until you leave that area. If you have all the drift ones, only make frequencies in drift. It eliminates about 15 of them. Do patrols, heroic public events and lost sectors. DO NOT DO EP. It doesn't give you any stems and is worthless

Forgive my ignorance, but where do you see which ones you've completed?