I don't know if BA monitor these boards, but can I say now that I'd definitely use a London - Hawaii service (and pay good money for it) at least a couple of times a year. Hawaii is one of my favourite places - a tropical parasdise where you don't need jabs, can drink the water, speak the language and the roads don't have potholes.
That said, to be honest I don't find it too painful to get off and stretch my legs in ORD, DFW or LAX (can you guess who my carrier of choice is

) on such a long journey.
San Diego is too close to LAX to be a viable route for BA. They'd be better off increasing the LHR -LAX frequency.