As mentioned, nufnuf (of this parish) is a travel agent specialising in these RTW tickets. He guided me when I bought the initial ticket but also pointed me towards code shared flights. I used Flight Connections.com and Expert Flyer to find routes to maximise miles and code shares to earn tier points by mileage, not fare paid.

He sorted the ticket plating and a lot of advice on routing ideas. Take a look at some of his posts, very interesting and showed me the way to fly round the world for the same price as I paid BA directly for a Singapore return last year that didn't even get me silver status when at the end of this trip I will have only flown on one BA flight number (OSL-LHR) yet achieve gold status until April 2028.

I'm already planning the next DONEx.

https://www.flyertalk.com/forum/members/nufnuf77.html