I think F-Line is taking one of his periodic sabbaticals from ArchBoston, so you may be out of luck there.
I'm not planning to drop 3,000 words, but I will say this about HRT to Everett: say what you will about the frequencies that branching will cause, say what you will about ridership projections for Everett vs Malden... none of it matters, because HRT to Everett is such an extreme long shot that it's basically not worth considering, nor particularly worth future-proofing for.
There are a few reasons why Everett HRT is so unrealistic. First of all, it would need to be a subway or an elevated in order to be effective. (The Saugus Branch ROW is too remote to be useful.) Depending how cynical you are, that may be enough to stop the proposal right there -- I'm honestly not sure that Boston will ever build a new rail subway or elevated ever again. But even if you're more optimistic, there's another hurdle: aside from streetcars, no rail has ever traveled through Everett. The vast majority of the T's subways were built on the footprints of railroad ROWs. There's nothing like that in Everett.
Even more -- the
vast majority of MBTA expansions -- extant and proposed -- are built on corridors that were identified 80-120 years ago. Boston's subway expansion business is exceptionally conservative and afraid of new ideas. In fact, in the last 50 years, there's been only
one subway expansion through a corridor that did not previously have rail on it, or previously be identified as a corridor for rapid transit: the Red Line from Harvard to Davis. And even if you go back one hundred years, there's only one other subway that was built "greenfield" (no previous mainline rail infrastructure in place): the Huntington Ave subway, and that had been identified by BERy as a rapid transit corridor a few decades prior.
Virtually all of the HRT expansions that are commonly discussed -- both in official documents and on forums like this one -- involve extensions along existing or abandoned-but-preserved ROWs.
- Orange to Roslindale Village, to West Roxbury
- Orange to Reading
- Blue to Lynn, to Salem, to Peabody
- Blue to Chelsea via SL3 alignment
- Red to Arlington, Lexington, 128 via Minuteman
- Red to Belmont, Waltham, 128
- even F-Line's "Red X" proposal leverages the Cabot Yard ROW for a significant fraction
There are a few others occasionally bandied about, but they are rare and mostly special cases. Blue-Red Connector is the most realistic of all of these, and is short and relatively well-studied. Blue-to-Kenmore and Red to Arlington via Route 2 are also exceptions, and are viewed with that much more scrutiny accordingly.
The closest comparison to constructing an HRT line to Everett is the Red Line extension north of Harvard. Greenfield corridor, subway construction. But Everett HRT has a number of challenges facing it that Red Northwest did not: water crossing, active rail ROW to parallel, and lack of diverted federal highway monies. The Red Line Northwest Extension was like catching lightning in a bottle: it's not something you can plan to replicate.
Barring political revolution (literal or figurative), HRT to Everett is not remotely realistic.