Just out of interest @ash666. Given that you can't visit the airport without complaint I'm wondering if you've ever considered complaining and I'd so what the response from the airport or perhaps considering an airport that better meets your needs?
Passport control can go from a slow trickle, to busy, to carnage and back to dead all within the space of 45 minutes. I doubt it's practical not required to hare anyone change the layout of the walkways continually throughout the day.
Im not aware of the automatic barriers being by invitation only. They're the default and barrier of choice now for the UK Border. If they're not available or blocked off then that's down to UKBA so I recommend younaddress your complaint to the,