Ideas
Simple solution:
Please go back to the same target desigantion/painting logic as BF. Meaning if a jet or heli is painted (should only be painted from a short distance not across the map), then players can only lock onto the painted target with dumb rockets like RPG and other dumb rocket launchers (also from across the map would make this too OP). Then you receive all the same warnings as a lock on missile and can be counter measured effectively.
This way helis have a chance to run away after flaring and they cant just hover anyways cuz we already have a lot of rocket launchers being fired and one hit from them or a tank's canon is already enough to shot helis down. This suggested compromise to lock ons will at least give flyers (esp helis) a fighting chance.