The only time Ive ever had a problem with killshooter is when a friendly tracking the same con as you pulls UP from UNDERNEATH you, into your guns......and even that has happened all of twice in two years.
In pretty much every other case ( the friendly is somewhere other than almost directly under you ) you definately should know he's there, especially with the external sounds of 1.08.
Try turning the external sounds up, and everything else down a bit, then turn system volume up, any plane, be it friendly or not, that comes within the range of your guns, can be HEARD.
Only thing I can think of, is get closer before you fire, makes the space the killshooter abusing dweebs out to ruin your day have to get into to have any fun, that much smaller :-)
No-one has 'dibs' on any particular con, to the guy who's airframe your ammo strikes, killshootering you, you are just some dweeb that started spraying and praying from too far back.
Takes two to Tango, and two to do allmost everything in this game, toejam doesnt just happen, you either cause it,or let it, by doing nothing to prevent it.
Same with Head Ons, vultching/being vultched, being outmanouvered by a Spit/Yak/N1k/Hurri etc

Just my 2c
<S> Blue