I just replicated a forthcoming booking in Eurotraveller for my wife (who is Blue) and for the first time came up with a request for gelt in return for pre-assigned seating.

Does BA's exemption for Golds also apply to any others on their booking? Should I try to link the two PNRs together to see what happens?

It's fair to say that if my wife will probably wrest control of future travel arrangements away from me (and BA) if she gets stuck in the middle seat at the back of the plane...