I think the fast track entitlement is down to the operating airline of the flight you're taking, not just because of your status.
I have a BAEC gold card and in Helsinki if the operating airline is BA then i'm NOT allowed through fast track (BA have not paid the airport for fast track security for anyone). If the operating airline is AY (even with a BA flight number) then fast track is allowed because AY have paid for it (presumably they pay for all OW status pax, not just their own AY status card holders).

At CPH I remember AY + BAEC gold meant fast track was included.