Don't know if anyone has posted this yet, but other than scouts, perhaps either adding a spy tech/cloak to the scout, or being able to research a spy plane of some kind that is undetectable unless your opponent researches the required spy detection tech .. ??
The "spyplane" could sit in an enemy gravwell and report via the gui any enemy fleet actions within its range. The report could include a pulsating curser around the spyplane to indicate the location of the detected movement?
Want to forego nerfing/tweaking the PJI somply add spy planes .. 
Tim-