Hi Lauri,
I was there a few days ago, lucky the crowd for tickets wasn't too bad.
BUT my walking partners had tickets for 12 o'clock and mine was for 2.30, just collected my ticket and walked right in, no one said anything about my ticket being 2 and a half hours early. I may have been lucky, but I got the idea that so long as you had a ticket, no one enforces the time slot rule.
They did want to see id at the ticket counter as claimed a OAP discount.
The Mozarabe from Almeria has been a bit of a beast at times, but what a Camino!!
Definitely a 10 out of 10.
Regards
George