My initial thought was to have it in covert operations in some way. I think we've got an entire side of the game which is begging for more practical usage instead of being used as a tool to piss people off.
Force players to use a slightly expensive covert operation against the planet being attacked for the duration of the attack which blinds a target from their attacker. Maybe you could get players using it before attacking, leaving an announcement to their target if they're around to see it. Alternatively you could force players to use it during the attack, if they want their fleet to be useless against incoming scans then they'd have to be around from launch until landing - unless they're happy with leaving their fleet open to scans after a certain point.
If you aren't keen on covert ops being used then maybe distorter ships could be added. Ships which can help prevent fleets being scanned, a certain number of ships could be required in a fleet to prevent scans being used on it - although less than the required amount could fiddle with the numbers in the scan. They could be expensive ships which are vulnerable and die easily, so if you land you could lose a few. It wouldn't prevent news scans, so you'd have one of the best aspects of Planetarion - instead of outright blocking you'd force people to calculate and guess what they've got incoming.
I know they're not exactly the best ideas.
I'd just like to see stealthy game playing which encourages people to guess a best estimate instead of the existing scan system being allow/deny if you've got enough amps. Allow anyone to scan, with the skilled players being the ones who can analyse them the best.