Any more recent experiences - I'm going to be doing YYZ-DEN on AC next week on the morning flight - 9:15a departure, so peak times. I have Nexus, though since I haven't seen additional reports, am I assuming the separate Nexus/GE entrance is still not open, and so one line to security? Is the premium security line open (not sure if I can use it, though have a US-based Amex plat which I assume should work if that part is running again, or at minimum would have pre-COVID).

Anything else special that needs to be done for the security/customs process compared to pre-COVID, aside from the form you have to fill out - I know AC has it linked to download so I can fill it out before I get to the airport.