Sounds like the same 'policy' in the US for many carriers.

Are you saying QF uniformly applies this policy to everyone? Irrespective of how you arrive, why delayed and you FF status?

Not that it changes the advice for OP, but for reference...if I am a QF P1, or an OW E, and an QF flight is late due to a mechanical...and I miss a QF outbound on a separate non-flex ticket.... I buy a new ticket? If it really is 100% inflexible that might change some future plans a bit.

Again, I know OP is on UA- and my comment made it sound like an non LCC might be better...Im asking as I want to know if AUS is grossly different that elsewhere in the world