I'm looking into a RTW itinerary ex SYD in July that will include Cuba, London and Shanghai, flying on AC and NH where possible. The best itinerary I can find is SYD-YVR-YYZ-VRA-YYZ-LHR-NRT-PVG-ICN-SYD, which according to Great Circle Mapper is 29,018 miles.

I suspect the answer is no, but is there any leeway for being such a small amount over the mileage limit? Or is that solely down to the discretion of the issuer? If need be we could fly VRA-YUL-LHR, which would get us down below the limit, but there's only 1 flight a week VRA-YUL at that time of year, and it forces an overnight in YUL, so that would be a last resort. Any info appreciated!

Incidentally, another seemingly sensible option would be to fly SYD-HNL-YYZ, however an itinerary including Cuba is not allowed to include any US city, unfortunately. Although the SYD-YVR flights touch down there, it is not included as a transit on the ticket, so that would slip under the radar.