I had to re-read the OP--I misread yesterday and assumed the OP was on EVA for the first leg...
OP mentioned (contract) agents at the counter in TPE forcedbthe Rouge connection in YVR. In hindsight, OP had access to (by virtue of their paid J ticket) AC concierge assistance in person at TPE. Two of the best Air Canada concierge agents in the world in were at the checkin counter/gate. They would have undoubtedly moved OP to whatever connection was desired.
Last year without asking AC TPE concierges have helped us in many ways, some documented on the Thanks Concierge thread.
Dang, now this topic makes me want to visit TPE a couple times before Feb29....
Last edited by expert7700; Jan 22, 2020 at 1:50 pm