I will post an update to this soon, but I do notice that my YYZ-YYC flight has OSS on the bp, for the first time ever (I have done at least half a dozen connections in YYZ from US airports in the last 2 months; the latest just last week and I have never seen OSS before). I am arriving in YYZ from the USA on AC. I am interested in whether there will be Nexus terminals available with the new process, and if having checked luggage makes a difference.