So you apply for the TUE at the same point you're planning to start T? Like it's a restrictive pain but there is a form to fill in to continue competing, you just have to do it before starting T if you're already competing? I don't see how any of that is different for under 18s.
Nope. You cant start until approved. And it's not as simple as filling out a form. You have to provide your entire medical history, psychiatric history, surgery history, deadname, bloodwork, and more.
You give all this to a panel of strangers who are likely going to deny you or revoke it a year later when you fail to have low T levels in the morning (which is impossible on therapeutic doses)