“Time in the right seat at a regional” is not a criteria used to determine competitiveness. I would apply now and update often. The only time you have to wait 6 months is if you start the hiring process (ie get the email to take the assessment) and somewhere along the way you get turned down. Having an app on file that isn’t competitive won’t result in a TBNT so no 6 month wait. You just won’t get called until you’re competitive.