Just a quick one, flying from LHR today and want to try the T5B lounge. It seems that people seem to have a bit of a soft spot for it but as you don't know your gate until relatively near boarding how do people know if they should/have time to use it?

Do people know how to get back to 'A' gates if required and just allow enough time, do they know in advance where they'll board from or do they just head there briefly when they know they're from a B gate?

Thanks as always. And apologies if this is covered elsewhere, I had a look but it didn't seem too obvious.