I have a oneway-award flight (total 13000 miles, the miles would have expired by the end of December 2021, Eco) that I would like to rebook/change to (2 options):
1) a return award flight (total 12600 miles, BIZ)
2) 2 oneway award flights (total 6300 miles, BIZ)

Online both options are not possible. A oneway-award flight can only be changed to a oneway-award but not return-award flight online.

But I guess option 1) should be possible at a TK office without loosing these expired miles? Is that correct?
And would option 2) be possible without loosing these miles that would have expired by December 2021?