If a ticket be it for football, cricket, music gigs or the circus says the gates open at 1:30pm but a show starts 2-3 hrs later people will always turn up in that time period as suits.
That isn't being a knob, tgat is having the choice, last I remember the official club advice was always "we ask/suggest" supporters arrive early not you must.
If timeslots were given with any entry requirements and set, the majority of people would turn up for that time, much like you would for a set appointment at an interview or the doctors.
When you have freedom to choose your arrival it is not knobbish to arrive at your leisure