Have only ever used Jokers on non-stop BA metal routes, so have a question about using them with a connection that is not operated by BA, given that it seems it will no longer be possible to open up extra redemption seats on non-stops if there is no A/D availability in F/CW.

If you have a route to a US destination LHR-XXX-YYY, with LHR-XXX operated by BA and XXX-YYY operated by AA (presumably under BA codeshare), does there have to be normal redemption availability for XXX-YYY in order to book this using a Joker? Assume LHR-XXX redemption availability can be opened with the Joker (my understanding is that BA can't open availability on AA-operated flights). If there is no redemption availability for XXX-YYY, is it possible to have a revenue fare on the ticket for this part of the journey, or is it simply not possible to book the routing usimg Avios for the TATL?

If it matters, would also be looking to use GUFs if possible on the booking for the BA sectors.