I am told that EK do not officially segment within individual tiers - once they get to a point where there are more people in a certain tier than available seats, it is entirely up to the controller who they pick.

Last priority will go to special meal holders and people with assistance booked. Also, check-in agents and lounge agents who encounter badly behaved/impolite members (EK or QF) regularly contact the controller to advise them not to offer a complimentary upgrade to that individual (As a side note, I approve of this ) - technically of course, all op-ups are entirely at the discretion of the controller, so this is perfectly fine. However, the reverse is not true, so blatant flattery and outright bribery unfortunately will get you nowhere

The tier grouping order goes EK iO -> QF CL -> EK Plat -> QF Plat -> EK Gold -> QF Gold -> EK Silver etc. etc. EKs flyers get priority over QF fliers in the same tier on EK operated flights. I assume the reverse is true on QF operated flights.