I have done 6 sectors in F this year, 2 to the USA, one to Japan plus the return trips back to the UK.

On all 6 occasions the crew held the J pax back until the F cabin had disembarked. ^

I was one of the first pax from the flight to reach the immigration line on all occasions.

At SFO and NRT the lines were non-existant

But my luck ran out at ORD and I was waiting 45 mins in line, in spite of being off first. Nothing BA could do about that though.