I think you're chasing for an alternative when the answer isn't Springfield. Your other thread captures the feeling of this post:

"It's not that Bostonians hate Springfield, it's that Bostonians don't think about Springfield."

Worcester gentrified because it was largely a commuter city that eventually attracted an industry (biotech), those employers that helped redevelop the city or the surrounding area, more people who came to live in proximity to their commute, and supporting services for those people (food, breweries). Employers will go where there's the most likelihood of the people they want to hire.

However, let's take a hypothetical. If Springfield follows a similar development path and grows proportionally in jobs, then the housing market will also increase to follow suit. You become priced out and will have to live somewhere to commute. You may find yourself back in a situation where "3 days a week would be too much".

If the commute is the issue, you can either move closer (more expensive), live further while having a job with an earning rate that is considered above market for your area (punching above your weight), or find a job closer to you that has in-market rates based on cost of living (par). I don't believe trying to change the character of Springfield or the Pioneer Valley will help with the commute issue. Bostonians don't think about Springfield because they don't live, much less visit there. Maybe if the East-West commute rail line project finally happens there's a possibility for better regional connections, but that's still a very long rail ride.