Yes, as noted in these threads, my experience was that A inventory showing on EF was not necessarily bookable by BA-MRU. When I was in Mauritius last week beginning my itinerary, I talked to the agent who set things up for me, and questioned her about the inability of BA-MRU to book flights when EF showed A seat availability. She didn't have an answer but did indicate some asymmetries in the system in that she knew that BA-UK could make bookings for A seats that BA-MRU could not. Whether they were holding them back from being gobbled up by RTW trips originating in MRU is not clear.