The main reason the RR is not available on the ERF is because they don't manufacture the 524-T anymore. The RR facility that produces the fan cases, the biggest and most expensive part of the engine, and the one that hopefully never has to be replaced at US$2 million, is now making only Trent items. The 524 is dead.
On the subject of thrust ratings all the CX fleet used to have 524H build standard engines (59,450lbs thrust) that were derated to 524G rating (58,000lbs thrust). Yes, with the -T core the build standard take-off ratings increased to 60,000lbs but CX continue to fly using the G rating right?
As you guy's with exotic motors in Hong Kong will appreciate, you have a car capable of 300kmh but you can only do 120kmh behind a PLB/Taxi/Bicycle. Or in the case of CX 744's you are always stuck behind one of your own A340-300's!
