Exulas, believe it. Above the Clouds is right.
2 notches of flap was commonly used for aeros and combat manoeuvring and it was indeed good up to 0.9M. Above that the nose down pitching moment exceeded the power in the tail plane PFCU (jack-stalling) and you ran out of pitch authority very quickly.
Things may have changed but that was how it worked last time I flew a Hunter.