I book all my flights as Avios flights, that works best for me. The only way to do this on BA to my destination (SDQ or PUJ) is to do direct. If I chose to do the one-stop, then it would involve flying to somewhere in the US (NYC, MIA or ATL) and then buying a cash ticket on either Delta or AA, risking the chance of a misconnect as it wouldn't be on the same PNR and having the sheer hell which is transiting in a US airport. Nobody in their right mind would do this to get a little door would they? I always pre-book my seat and usually get one of the window seats which has aisle access (there are 2 of these on the old LGW 777's).