I think it's a fair point that F should be given the opportunity to board first., if they wish. No group allocation needed just a simple "First passengers should make themselves known and board at their leisure".

I'm Gold and regardless of class or length of flight, my preference is to board among the last. I prefer to be on two legs for as long as possible ahead of being on my backside for hours on end (another reason why so many folk stand at Gates rather than sit). The only exception is for an overnight when I board as soon as possible, eye mask on and asleep before doors closes or if I feel there's going to be a risk of cabin bag going in the hold.