Had OSS on my SFO-YVR boarding card. Was handed a yellow card on arrival, continued to the Nexus machines and went down some corridors to be ejected near domestic security. Asked the SE check-in if I did something wrong. SE checkin thought OSS meant I had priority security privileges, their ignorance is quite funny considering it's an AC boarding card and I told them it represented "one stop security." They do work at the airport though, so what do I know.

Maybe it's coming soon, and maybe it will allow use of the Nexus machines.