Moderator, Air Canada; FlyerTalk Evangelist
Join Date: Feb 2015
Location: YYC
Programs: AC SE MM, FB Plat, WS Plat, BA Silver, Marriott Plat, Hilton Gold, Accor Gold
Posts: 18,942
If the fare allows more stopovers, you could consider booking it as YYZ-YVR (stop)-TPE; HND-YYZ or YVR-TPE; HND-YYZ (stop)-YVR. Some of the stopover allowances on AC's international fares are quite generous and the stop could be several months long.
This may eliminate the double open jaw and give you some better options in PE/J.