I haven't done one for a while, but it used to be that almost no travel agents were capable of doing anything useful re any xONEx bookings, and we just used them to get around point-of-sale pricing rules. It also used to be true that only a few airlines had dedicated RTW agents with enough experience and knowledge to correctly interpret the rules in making a booking. AA was the best, and even they melted down as AA morphed into USdbaAA. Afaik, the good folk here at FT are your best resource.