How about this?
I believe the HKAOA should look at the pilots being offered employment at CX as an investment. Have them join the union before accepting employment at CX, and them pay them their salary while the hiring ban is in effect. Once the dispute is resolved, they can officially accept employment with CX and avoid being put on the glorious list of scabs......that is somewhat similar to what ALPA does in the US, i.e., when a pilot group goes on strike, other pilots groups pay their strike salary.
It seems to me only fair that if the HKAOA/IFALPA/ALPA wants prospective new pilots' support, they should provide evidence to them of the union's commitment to fair representation!