It seems impossible to kinetically defeat or flare these missiles from a pure rear aspect, even on cold aircraft like the f-5c and e. You can easily zig zag on aim9j’s with these two planes because they have good energy retention, yet somehow hunter f58s keep scoring FLw>Z or whatever they called kills CONSTANTLY against flaring aircraft.
Edit: I remember AIM9J’s also ignore flares sometimes especially on terminal approach. Hunter F68 is very slow and happens to launch these missiles far away.