This industry is volatile and cyclical.
It’s very hard to predict how long every cycle will last and where we currently are in the high.
Between the economic events of 9-11 and 2008 we had 7 years which each took 3-4 years to recover from.

1500 hrs for a Regional job will take you approximately 3 years. That may just puts you at the end of a good cycle or the end of a bad depending when you start training.
After the 3 years for the 1500hrs it will take another 2-3 years before you start making decent money. That’s 6 years total and very hard to predict where the industry will be.
Yea the Regionals now have flow and signing bonuses. Don’t count on a signing bonus to pay off your loan, that’s gambling.

In short try and do this with minimum debt and preferable you keep your day job.
Get rid of all debt and start saving.