Lookleft, can't speak for the Jetstar FRMS but the Virgin FRMS bears no relationship to the Cao 48 exemption and if you worked there you would know that.
No FRMS is perfect, and a FRMS is more than just the work rules, it is how you manage individual fatigue, how the business treats staff that go fatigued, how the business is proactive about ensuring pairings are not fatiguing and how the troops feel about reporting fatigue, even if they have not removed themselves from duty for fatigue reasons.
None of those things are in the CAO 48 exemption and individuals react to different stressors in relation to fatigue differently, so what is fatiguing for me may not be for you.