There is plenty of spacing between Superchargers in MA for even a range-limited Model S 60s to be able to transition the area successfully, so I think Tesla has done a heck of a job. (IMHO, the worse thing is traveling on a Saturday and arriving at a Supercharger as an interim waypoint only to find it full of locals doing their weekly charging. having a 25 minute charge stop turn into an hour waiting for the locals to clear out sucks)
The Feds changed a few years ago how they prioritize the signage. If you're over 35 years old, there is a time where 128 was more prominent on the signage than 95. We can tell where you're from, how old you are and/or how long you've lived here based on your observation.
Ah, I miss the good old days, when you could be traveling on 128 southbound and I-93 northbound at the same time...
You can still go on I-95/MA-128 southbound and on US-1 northbound at the same time between Dedham and Canton.