Flypast: I think that BA will keep well away from this idea! Some of the new 777 that for high density routes, such as Florida, have been specially configured to be 10 seat rows, rather than 9. They use narrow seats and aisles and are then able to get nearly 100 extra seats (I stand to be corrected). As freight is not a main feature of these flights, they can take the weight.
When they were first introduced, they faced an action by a pax who was shown a seat layout of the conventional 9-in a row but found himself on the 10-in a row. If I recall correctly, they settled out of court.
The 10-in a row is not used on all their 777s.
CB: As I have already pointed out. My gripe about IOM flight cost is one of monopoly and lack of interest by the IOM govt. Please do not take the trhead off course with repeat postings of information that I have already corrected. However, I am pleased that you remember my posts so well, given that I made that post more months ago than I can recall.