Originally Posted by
jope_taco
My experience:
- If you buy-up to Premium prior to T-24h, your ticket changes to R, and your odds of an upgrade to J increase (you would need to reapply instruments)
- If you buy-up to Premium within T-24h, your ticket does not change and there is not even an option to try to upgrade further (seat map shows all seats in J and Eco greyed out; only PP seats available for selection).
From my experience and my guess (see floor #6), in your later case, there is no option to upgrade further directly while your instrument stay with your reservation, so that you may still get clear via Miles+Copay.