My in-laws live in Toronto, and we are thinking of leaving my son there while we go to Quebec. I've already purchased the flights to return to AUS from YQB (AC1793 -> AC597). We have a 1.5 hour connection in YYZ and I'm trying to figure out exactly how the connection works so we can pick him up as we connect in YYZ. He's 9 years old, and Air Canada told me that if he is transiting security alone (or with his grandparents), he'd need to be registered as an unaccompanied minor, even though he'd actually be flying with us.

I understand from Air Canada's website that we need to go through security again in Toronto, but what I can't figure out is if the security described on that page is a bypass security or if it is the same security as someone departing from Toronto would take. And is the "US Connection Hall" different from the main CBP area? If they are different, how would one go about fully exiting to meet someone, and what would be the time impact on doing so.

We all have Nexus.

Thanks for any advice / thoughts.