My father has a $3K+ FFC from a business class flight he had to cancel for medical reasons. It is expiring in Jan 2025 and he has no travel plans before then. He does plan to buy another biz ticket to Europe next summer. From perusing this thread it appears his only hope to use his FFC is to book a flight to Europe in Dec, wait for it to ticket, then change the dates to when he really wants to travel. My questions:

1) Is there any angle he can use to get an extension to the FFC due to the cancellation of the original flight being for medical reasons?
2) If he books a Dec ticket, and changes the dates, does the Dec ticket need to be in the same class of service (business) as he wants for the summer?
3) Does the Dec ticket need to have the exact same routing as what he eventually wants for the summer?
4) Does the Dec ticket need to have no change fees? I believe change fees only apply to Basic Econ tickets, so if he's buying J it should be a non-issue.

Don't fly UA often, so not too familiar with all the ins and outs - appreciate any help. Thx!