Possible to upgrade one leg (return) of KE paid J flight to F using AS miles?
I flew from SFO to ICN a week ago in KE J and will be returning to SFO in another week. Ticket was paid J RT, credited to my AS mileage account. KE website shows that there are open F seats on the return that are eligible for mileage upgrades (presumably using KE miles).
Does anyone know if it's possible to use AS miles to upgrade from J to F on one leg of a paid J ticket?
And if so, do you know the mileage cost to do so for ICN-SFO (and whether I'd effectively be paying double, like for KE award tickets where you pay the RT miles price even for one-ways)?