Multi doesn't matter for regioanals anymore, you just need ATP ME mins minus 25 hours (they can give you 25 in the sim).

It's not too late to make it to a major, due to legacy retirements, and I would focus on that. While regional pay is great for what they do these days, all regionals are stressed by staffing and there's no guarantee that the regionals will exist in current form by the time you reach 65.

If everything slows down and you get stuck at a regional, you'll probably still have a good career. But shoot for the majors, it's just that much better unless you already have 25 years longevity at a regional.