For the most part MA. has a common sense approach to the code, if something has worked for years without trouble they will not make a change.
We can still feed down to a switch using the white of two wire cable and return on the black.
Qualified people know this, so why change now.
We also have a less restrictive derating chart we use for more than 3 current carrying conductors in a raceway.
We use the NEC with about 70 to 80 changes to it.
Bob, South of Boston, MA
Construction & Maintenance Electrician