I do have an Asia Miles account, although never use it as I am BA Gold...
We have 2 vouchers per person... "This voucher entitles .... to a one-class, one-sector complimentary upgrade, based on seat availability at the time of check-in."
If I can extend them or turn them into Miles, I'd be much happier! I have asked Cathay for Asia Miles instead, so am waiting to hear from them.