If checking in at HKG, you will be given a lounge pass. If not ask for one and explain that you are now E. You might get a printout of your account showing you are now Elite to use as proof if you are checking in at connections where checkin is done by UA agents (not sure they have access to AC files). If checking in outside security, you should be OK and they should give you a pass. I get one every time . . .