Go a bit earlier and relax in the lounge. Reduces those moments of stress when the train stops for no reason or you get behind someone with problems in the queues.

Not BA, and not F, but when I flew recently in J a problem family had been transferred to the single J check-in just before I arrived so after 5 minutes behind them I had to join the Y queue. Had minutes mattered I would have been worrried about making a tight departure.

I will let someone else develop the joke inherent in the above!