Given the morning rush 33 departures ph is designed on a single runway, even though dual is allowed it is not always possible hence the cap not been increased. Can it really be the problem, I think it's the return sectors with handling issues where the real issue is as you say. Compounded by the FCO mess.
Can we expect some contract changes where EI don't match BA/IB in handling at some stage and I think service may improve. OTP and Catering are issues which need immediate attention.