Cathay has just priced a AONE3 ex-Tokyo for me in super quick time, it took 7 hours from my original email for them to reply. Apart from a couple of very minor code share issues it looks good. The £900 in fees and taxes are not so good, but that's what happens if you include LHR...

For peace of mind I want to confirm that all I need to do to change any flight dates (I don't start until May next year but I want to get it priced ASAP to take advantage of the favourable rates) is email Cathay at Tokyo with the revised dates once I've taken my first flight. I've included a number of dummy dates as part of the booking but obviously I can't set these beyond a year from now. Once the first flight is taken I should be able to change these to any dates as long as they are within 12 months of the first flight. Is this correct?