Want to clarify - Are they able to pre-register on Feb 2, same as Standard badges? It looks like it, from the way the blocks of badges types are set up. https://tabletop.events/conventions/gary-con-xi/badgetypes But the wording is a little different. And I believe single day badges didn't get pre-reg in the past.
Interestingly, the Friday badge is allowing me to buy Friday events, but the Thursday badge will not allow me to buy Thursday events
That's a tech support for TTE question, my man. Click the big ? in the lower right corner, and go through the questions there. If that doesn't help you, click the Contact Us link. That'll submit a ticket to the TTE system, and a rep will be right on it.
Superfast response from TTE (& their GC contact) Any of you other 4 Thursday only folks should be set now