I think this would change the game for the better.
Even if 1 in 5 shots hits, it promotes movement, and like another poster said, icarus lacks reasons for movement.
Flare lock-on is bad for gameplay however, and also difficult to code.
Magnetic or heat guidance is basically the same under a different name. I think we don't want heat seeking missiles.
This is unreal engine right? In that case, "follow the crosshairs" guidance is hardcoded into it. That could be used, but with very slow turn rate. If another missile is fired, previous missile becomes dumb-fire.