Unlike many other airlines, BA give First customers zero priority on boarding other than being herded in with group 1 (or in some cases groups 1 to 3). All this is after, on some routes, half a plane of families have boarded.

Emirates, Qatar a several others all board First first, as it should be for the premium paid on the fare.

I comment on this every time I am sent a post flight BA survey, and have done for many years, but nothing changes.