Originally Posted by
SEW247
If so, can I do this immediately after I've booked my outbound flights
Nope. You can't do anything until T-355 at the earliest, and then only if you see availability.
Originally Posted by
SEW247
or do I need to wait the 355 days to call them once the flights are released and cross my fingers that I can get the returns flights?
Yes, cross everything, wait to see availability (it may or may not be at exactly T-355) , then get on the phone pronto.