I'm not aiming for a massive simultaneous assassination, but currently I am extremely aggressive with my neutering. Perhaps abnormally so, given the new guard post difficulty, and my normal use of currently unavailable superweapons. I currently have every single adjacent planet neutered, but since I'm hoping to push forward and grab fabricators and starship constructors before sealing off my area and clearing out the backworlds, I figure it'll save me a headache with all these eyes and fortresses.
...I might give in to save scumming once I've reached that point, and see what happens when I pop 10-30 systems in the course of an hour.