Hi all, I'm looking to book a one way CX flight in First using BAEC Avios or Advantage miles from HK to Europe in November 2021 (any destination in their network is suitable, as I will buy separate flight to London). There's plenty of 1 seat in First to CDG, FRA and MXP - however any ideas on how long it takes to get a second seat appear for redemption?
Any routes where First is likely to open up more seats?
Or if there is any alerts you can sign up to (I have Seat Spy for BA/VS so anything similar)?

I'm travelling in a pair so could do with the second if available...