Connecting back from the U.S. through YYZ to YOW right now. Landed thinking it would be quiet at noon on a Tuesday - nope, the U.S to Canada OSS customs connection area looks like the shopping mall on Christmas Eve. Looked like there was north of 100 people in line, through the glass it looked like two agents working and of course they still have no NEXUS for OSS.
I just went downstairs, went through Customs with NEXUS in 30 seconds, and went upstairs and took a peek at second floor security before going to NEXUS security on the third floor. Second floor security has no line, so I walk up and am through there in another two minutes and at the D gates; rest of the airport is pretty quiet as you'd expect at this time of day.
I'm not sure what landed just before me, but if Pearson / Air Canada want to make this a better experience for the masses who don't know better than to skip OSS when it looks like that then they need to ensure that transit OSS can actually accommodate the load.