I have several CX segments as part of OWE (First Class) upcoming in August. Everytime I check, the people at the AA RTW desk say that they cannot assign CX seats this far out.

Does anyone know how far in advance one can get a CX seat assignment?

If I was to call CX directly, would I be able to before AA can do it?

Finally, if I am on a two class service flown by a three class aircraft (343), how do I go about getting a first class seat assignment?

Thanks!