They hold YYZ if long haul inbound are late, I mean not forever, but they held it once 90 minutes when I was in PTY for a late flight in from Buenos Aires. They do not want 20+ people stranded in PTY for missing a once daily flight to Toronto. That said Copa has about a 92% OTP record and they shade the arrival times (hence the 92%) so I would not waste 8 hours on this contingency. 1 1/2 hours is boring enough. The lounge is as crowded as a bus station as well which does not add to the ambience.

If you are in the (short and fast) queue for the YYZ gates they are not shutting the door on you, clearly. And J gets to go ahead of Y.

I have no idea why they persist on this silly behaviour, other than to parrot the USA. It's fun to watch them chit chat with each other, you, anyone, while stuff goes through the x-ray with nobody looking at the screen. Computer out? Shoes off? Nah, don't bother.

SJO does nothing of the sort for AV or WS flights to Toronto (nor does HKG though they still segregate USA flights) so it's not all airports nor both countries, all the time.

And MGA has stopped with the segregated gates to MIA though they do "randomly" inspect people at the jetway, "randomly" being defined as people dumb enough to shove to the front to be first in boarding in J. I let 3 people take one for the team then never get stopped, so quite a foolproof system. SAL still does but it is amazing to watch them handle 500+ people at 7 a.m. in about 15 minutes. Like a Ford assembly line. I doubt it is all that thorough either.

Not to worry in PTY other than the gate areas post inspection are on the small side. Central America - the hobgoblin of inconsistency with this security theatre.