Glad to be of service as well as take part in this interesting discussion.
In a month or two I plan to revisit the New York Public Library's Special Collections Division (I have to renew the special card you need) and I want to look at Wilgus' Bronx plan in more detail. When he listed the various alternatives to providing electric service through the Park Avenue tunnel to Grand Central he called the Bronx option "the clearing house" plan.
Also, if I can diverge slightly, as to why the Bronx civic leaders desired a large and elaborate passenger station at 149th Street. The Bronx was then (especially the southeast Bronx) literally booming with new industry. The Bronx leaders believed that a supporting office district would sprout up too (it never did) and hoped to guide it to the area around E.149th and the Grand Concourse, anchored by a large passenger station.
The thinking by 1900 was that Manhattan's office district would continue to expand as it had done over the previous fifty years. The commercial or office district in Manhattan had expanded over the second half of the 19th century from Lower Manhattan to the 42nd Street area. Many planners in the early 1900s fully expected this trend of northward expansion to continue. Many believed by 1950 E.125th Street would be a major business corridor. Bronxites hoped a satelite district would be established near 149th Street.
This was part of the reason why, around the same time period, the New York Westchester & Boston was comfortable with locating their city passenger terminal at E.132nd Street, just north of the Harlem River in the Bronx.
What the planners did not foresee was the evolution of the modern skyscaper. Manhattan continued to grow alright, but
up not
out.