my experience with CX (at least in TPE) on RTW is that they are not really fully aware of the "correct" rules and often just impose their own thinking, usually similar to some of their existing non-RTW fares, e.g. during my various interactions with CX TPE through my TPE agent:

• sometimes they insisted that I have too many stopovers when some of those are not really stopovers, just simply overnight <24 hours - needed a few back-and-forth and requested that they checked with CX HQ in HKG to resolve - they just simply assumed that overnight = stopovers
• they insisted that e.g. TPE-HKG(stopover)-USA-Europe-HKG-TPE is not ok because for most other roundtrip US/Europe fares they have, only stopover in HKG on the return is allowed and not on the outbound - so they just assume it's not ok with RTW as well and again I needed a few back-and-forth before they gave me the correct answer
• another one not with TPE, but if I remember right it's a routing like PVG-Europe-US-HKG-NRT-HKG(stop)-BKK(stop)-HKG...eventually I wanted to change the BKK to NRT again as well, but they again immediately said it's not ok because I have had HKG-NRT-HKG once already in the itin - but again if I remember right there's nothing in the RTW fare rule prohibiting this and again in the end after a few rounds of argument they agreed it's allowed

I'm myself right now again dealing with them to reroute an AONE3 as well - when there's nothing in the rule prohibiting what I'm doing and they for some reason again said no...