Originally Posted by
findark
I'm considering the scenario where a non-refundable ticket is changed to a refundable fare. I think you can then cancel the refundable fare, and the "refund to original payment" would mean an ETC for the part paid by the non-refundable ticket's coupon (and the extra money actually back to you). This is less advantageous than simply changing the original ticket to something you do, in fact, want to fly.
Wow. Interesting strategy. So OP could buy a more expensive ticket, pay the change fee, and get the entire orig value back as an ETC? That's actually better than the standard LAX-LAS method, in which one pays the change fee + dummy fare.
OP: You want to wait for a sked chg as others have mentioned. But if you do have to cancel and extract funds, it's best wait until the last minute since the ETC will have a fresh expiration date. Of course, the best solution is to have a UA operated itin lined up!