abbotyobs,
The problem is not so much with Cathay as the Chinese CAA. when converting your license to a Chinese one they want to see what marks you got in which exams. Consequently, trying to explain how the Mil license works baffles them and they say 'non' ...... or whatever 'no' is in Chinese.
At the early stages of the 'Mil dispensations JAR license', I am led to believe, a couple of guys with such licenses did get in Cathay and Dragonair 'under the radar' but then the Chinese CAA put their foot down and stopped it. Consequently Cathay, and others, said they wanted all the exams done to avoid jousting with their CAA. So, it is a problem with any of the Chinese airlines.
That said, I recall that a friend, with such a license, did get 'promising noises' from Cathay and did the whole of their recruiting process. What the outcome was I do not know. You will really have to try and touch base with someone in Cathay/Dragonair or similar who can get up to date gen.
Best of luck.
Why do you believe BA will keep the 'window' open past 31 May? I think it will be more like closing this recruiting round and, if necessary, opening another later in the year. Thats the way it usually happens.