Originally Posted by
JALPak
Redemption on PG needs to go through the phone. No registration is required.
Thank you, JALPak!

I just gave them a call. Took awhile to get through to their Awards center. The CSR was a bit confused about the promotion and hadn't heard about it before ("we have a lot of promotions going on, sorry...*flip flip flip through binder*").
Availability seems to be very good and open; had no problems with the flight I needed in December for BKK-RGN.