Your best bet is to wait for the HK server 5am reset in 6 hours and ask those from the HK servers, cause at the moment, no one knows the exchange rewards. Then depending on your time zone, you might have 1 hour to decide before this Fateful Choice closes at your midnight time.

Actually, I apologise. I got my dates wrong! I kept thinking the next day was the 31st. So there was actually no way to make that decision based on what I previously said. Sorry for the misinformation!