Speaking of crosstown service, I noticed on this map that the 42nd St. shuttle is not planned to extend across to the new Second Ave. line:
https://upload.wikimedia.org/wikiped...way_Map_vc.jpg
I understand that the trackwork that made the shuttle possible is pretty random and complicated, but it goes without saying that extending that shuttle across would be huge. There was a proposal to extend the shuttle to Grand Central, so there might be a way to get past it toward Second Ave.
Also, looking at the Phase 3 and 4 plan again, it's unfortunate that the line won't be able to interchange with 6 or 7 of the lines that it crosses, at least under the tentative plan. Are they planning an underground walk to connect the 14th St. station with the two nearby L stations? If so, it's not indicated on these graphics.
I think by building this bashful all-local Second Ave. line they're missing the opportunity to build an all-new line that introduces a greater depth of redundancy into the overall system that will enable the city to keep moving when there is an accident or need for extended repairs to the north/south lines that have express tracks.
Threaded Mode