Basically! It'd likely have really limited utility for not-office park / mall based folks, but the sheer concentration of those types of workplaces in finite pockets along the 128 Corridor, from Danvers to Quincy makes it interesting to me. I'm basically imagining the 128 Alewife shuttles, just PnR oriented. The diversions would possibly be a problem, but with some sort of "traffic skip," especially in your open BRT concept, they'd probably be able to make up that time whenever there's meaningful traffic, absent local congestion.
Generally, I think complexity is a deterrent to transit ridership, so I probably wouldn't extend it along the radial highways, at least not as a first step. Connections seem dicey to me, and I don't think you usually see too much traffic on those radial highways until I95. Although there's similar office park density on I90 / the I495 ring, a lot of office parks are off corridor. I think it would all depend on whether there'd be demand for that out further where there isn't as much traffic.
