So I've been trying to work out a route in J to go YYZ - Tokyo - Hong Kong - Hawaii - YYZ for a little bit - just wanted to share some findings:
HKG-HNL is a very difficult route - you have to stop through either NRT or GUM and availability for HKG-GUM and NRT-HNL is tough, a lot of the times it ends up being only available through HKG-NRT-GUM-HNL which kills your MPM
I then tried to open jaw from Hawaii in the folowing route:
YYZ-NRT (stop)
HND-HKG
HNL-ORD-YYZ
But turns out your open jaw must be in your DESTINATION IATA - despite me trying to protest that you can have it in your origin IATA group - the (actually quite helpful) agent tried to put it through but it was not allowed - so conclusion is that you must go through an Asia 1 city if you were to open jaw with HKG as your destination
HNL is just a difficult place to get to in general in J, UA availability doesn't seem great.
My final route will likely be something like:
YYZ-NRT (stop)
HND-HKG (destination)
HKG-BKK
BKK-TPE
TPE-SEA (stop)
SEA-YYZ
Not sure if this is valid but would get my own RT ticket in Y to HNL from SEA
alternatively I might just go this:
YYZ-NRT (stop)
HND-HKG (destination)
TPE-SEA (open jaw)
SEA-YYZ (hidden city)
Then just buy a SEA-HNL-YYZ ticket which isn't much more than an RT.
Hope this has been helpful - searching this route has been a pain because of the NRT/HND possibility out of asia but not much luck. Let me know if anyone have any suggestions otherwise hope this helps others planning a similar route.