Thanks everyone. Your info has been most useful and I have given up on the staff travel idea. I had bought full fare SYD - HKG, but have found a full fare SYD -LHR with BA that is only £50 more so am going with that.
Really appreciate all the good gen on this - you have helped my decision making hugely! Hope I can repay the favour someday (if I still have a job 🙄
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All the very best to all,
Mike