I’d add Spirit to your list. MCO and MIA/FLL. Spirit has Y list where you get paid 200% if they call you. You can list for the Y list anywhere you can get to within a couple of hours that Spirit operates. Once you’re off reserve, you can fly all you want, within the 117 rules.
Either way, ULCC > Regional. If the music stops, you can have a nice career at a ULCC with a real retirement.