Once again, if the Gateline is set appropriately, none of the above is required.
I gave a random example earlier - lets try a specific one... Lets be specific.
Between 1745 and 1815 on platforms 1-6 at Paddington ^ all of which are either unbarriered or controlled by the same gates^you have the following scheduled departures.
Platform 5 1745 Swansea
Platform 1 1748 Cheltenham
Platform 2 1800 Bristol
Platform 4 1803 Golden Hind
Platform 3 1815 Swansea
Only one of them does not set down at Reading. How can you properly control the barriers / gateline to stop reading passengers accessing the platform for the 1803?
Setting the specific rule and applying it to the gate array takes less than a minute. Even less if you are well rehearsed!