...knowing where they will be for 2 turns was even more fun
Quick interjection: I might be misunderstanding your meaning on this, but are you referring to the two ion tokens from IPM? Because:
After completing the white 1 forward, your opponent would remove all ion tokens and be free to maneuver the next time (unless ion'd or otherwise restricted again). They don't stack like stress.
The two tokens at once thing from the missiles is for ionizing large base ships with one shot.