I'm making my first trip on CX to HKG from SFO and am hoping to upgrade from PEY to Business. I'm MP Green for now and I tentatively booked 21 May CX873 a month ago . I am waitlisted for a AM upgrade but the loading (from ExpertFlyer) isn't looking good (J3) as of today. I'm flexible within a day or two; Would it make sense to shift to CX879 (J9), or to 22 MAY CX873 (J7), CX 879 (J9), CX893 (J9)?