Has anyone tried a turnaround here on CX? I need to get >2700 mile segments to earn more status credits on QF, and this is the only Asian segment that fits.

Question is, what are my chances of a) not having to pass through passport control b) getting my B.P. in advance i.e. when I check in in HKG c) stuff generally going wrong -- if I miss the return I'm stuck there for 2 days!!

Thanks,
Chris