Getting flying. It's that simple.
If you get hired one month earlier the extra month at the end of your career will put you ahead. And you'll be 50-100 numbers more senior every single month of your career.
And if DL doesn't come through what's Plan B? Go back in time 2-6 months and take the regional job that you passed on while waiting for 'the call'?
You're a better candidate at the table when they ask "so you retired X months ago. What have you done in the meantime?" You'll never have to apologize for saying "I took a regional job to learn a new a/c, cross over to passenger 121 flying, and to get back to my first love which is flying airplanes."