Originally Posted by
zrh2yvr
On the Canada comment - this is mostly true but - at YVR - the international departures are secure and you are not allowed to leave to immigration and exit without an escort (and a reason). But - you would not likely be locked in like HKG.
Anywhere there is a Customs Controlled Area within departures in Canada, you need an escort to leave.
https://www.cbsa-asfc.gc.ca/security...a-zcd-eng.html