Is there a rule that prohibits upgrading a CX sector using Asia Miles on an RTW? I thought it would be the same as upgrading an AA sector using AA miles or VIPs, but the RTW desk tells me it's against the rules, and they will cancel the upgrade. It seems CX/AM won't take over the reservation and re-issue the ticket.

There's text in the The oneworld explorer ticket FAQs thread that says this is OK.