Assuming I'm doing a 4 continent OWE, in this order: Europe-US-Asia-Australia-Europe, would this be a legal routing to get from Australia to Europe, assuming all 4 segments in Asia are used before entering Oz:

bne-syd-hkg-nrt-lhr

I have a ticket now with bne-syd-nrt-lhr, but i was thinking it might be legal to use CX via HKG to NRT and then BA from there and home?