Yes, that is a good point. It worked seamlessly last month when I was on a paid booking, and had my mother (Blue) join me using a redemption ticket for one part of the journey. 64 A/B were right there for us (well, 64J had settled into 64A, but that was another matter and quickly sorted).

If enough people remind me of little things like this - or BA makes such benefits official - maybe I will be bothered to renew gold next time around!