Personally I think DUB would be an ideal airport for this. Currently in T1, the DAA lounge is used by every airline including LH, LX, TK, KL plus the oneworld airlines. BA operate up to 14 flights a day to LHR & LCY. IB, CX, QR, AY & S7 also operate from T1 so between those in business and OW FFers, there’s enough demand IMO