This tower was never 50 floors, and never had any major design changes. There were some modest modifications based on revised DOB guidance mid-construction, but the tower, as-built, is essentially as originally rendered.
A theoretical true 50-floor superluxury condo tower, on the UES, would probably be pushing 900 ft. these days. It might even hit supertall status. Adding in mechanical space, lobby and amenity space, and you can get real height. Buyers at this price range want high ceilings in new construction.
I found the article that mentions some sort of Tax lot zoning violation; there are a variety of other technicalities involved I don’t quite understand - but all is well, that ends well. This is a fine edifice.
EXCERPT FROM ARTICLE - …Speaking of Upper East Side NIMBYs—neighborhood residents are in a tizzy because of developer DDG’s sly ploy to skirt zoning regulations by creating two different taxable zoning lots out of a parcel, allowing it to push its tower back from the street and avoid the attendant street-side requirements, The New York Times reports. “The fast-rising 521-foot tower, known as 180 East 88th Street and approved by the city’s Buildings Department, now faces a challenge from residents and elected officials arguing that the developers, who donated at least $19,900 to Mayor Bill de Blasio’s campaign and causes, used a novel tactic to circumvent zoning regulations and build taller than would ordinarily be allowed.”