If AC didn't want you to do an international check-in on the kiosks, I think that they would block it in the kiosk itself. It is possible that the yellow passes have been introduced so that international check-in is possible.
ps - ni hao from Beijing. I am studying here for the semester. I had a great AC flight over and the baggage delivery here is faster than any AC station around - including coming off a BEH 1900 in GRR. Fire me an e-mail if any of you will be in town sometime this fall.