With 3 days to spare, I called Fortune Wings Club to inquire about an (unlikely) extension.

One of the English-speaking agents emailed me a tip...that actually worked!

You can donate just 1 point as a carbon offset donation, and that resets the activity timer for expiration. The transaction posted immediately, and my expiration was extended to 2023.
https://trip.hnair.com/frontend/greenFrontend/donate

PDF instructions from the agent attached - I was able to get through some of the errors by using just my last name and 10 digit US phone number.