I think the poster above is correct that the second YZR is probably YVR. Judging by the type of planes at YZR, I dont think YZR would connect directly to TPE, or even YYC.

YYC-YZR Y AC 3H
YZR-TPE J AC 14H

Also well done on planning this, I dont believe AP would have allowed backtracking at YYZ if YZR was not your destination. They aren't that flexible.