Why not do TPE-PVG first, then
PVG-YVR-YYZ-PVG in Latitude (or PVG-YYZ-YVR-YYZ-PVG if the days don't work)? It would add a few hours, but worth it to get upgraded across the pacific both ways imho
You would, I believe, still need to call an agent to get YVR-YYZ in T/T+
That will be a good option if I have 3 SWUs, but I have only 2 SWUs from my E package, and it will be used for YVR-YYZ seg and YYZ-PVG seg. Plus, I would like to keep my TPE-YVR flight since I'm a AC Elite and BR Gold(double the priority

) and a very frequent flyer on this route(6-10 each year). I can say most of the time I can score an upgrade to either Elite Class(Premium Economy) or J when the flight is not too full(ITC, november is cold on this route).
Thanks for the advice and will certainly consider it next time I fly to YVR.
Oh ya I don't have to pay phone reservation fee to book this right?