How about granting extra score/perks to players who use a new, extra icon option which only shows you the range of enemy aircraft, and only does so at much closer range (say 2.4 instead of 5.9, and only inside 600 below dar), as well as for players who fly in friendly only icon mode.
The one caveat is that the enemy-icon-mode setting would have to be selected prior to takeoff and would need to apply for the entire sortie.