If we had a situation of queues (which I don’t think we will) then there would *have* to be priority for certain people. The impact of, say, a LNER driver travelling to work on GTR not being able to book-on at the correct time would be catastrophic.
Also if they end up waiting hours to get home having missed their booked ticket train because of running late themself and come in late the next day because of fatigue.