It seems silly, especially since it’s called an e-ticket.
Make sure not to fold or damage your E-ticket!
"The barcode on the e-ticket can't be folded or damaged. When the e-ticket is damaged access can be refused."
Just pay at the entrance. There is never a queue there.
Thanks. We paid at the door - no queue - and had a wonderful time! I’ll give it 5* when I’m at my computer with a proper keyboard.