The linked post says you can't go to byutickets.com and find basketball or football tickets to buy if you are logged in. You have to make sure you are logged out, go through the process of selecting your tickets, then not log in until you get to your shopping cart at the end of the process. I found that hard to believe, so I decided to test it...
I just went to byutickets.com. Went to the login page and logged in, then went back to the home page.
From there I selected BYU basketball, and then selected "Single game tickets".
That brought up a page of upcoming games. I clicked on "Find tickets" for tomorrow night's Nevada game. That brought up a map of the arena. I chose a section, then chose 2 seats in that section and hit "continue", which took me to my shopping cart.
From there I selected my delivery method and hit the big green "checkout" button. On the checkout page, I entered by payment method and clicked the blue "Place your order" button.
tldr; I was just able to select and purchase BYU basketball tickets while being logged in the entire time.