Bar Wayo, the latest restaurant from David Chang’s Momofuku Group, sits at the edge of Pier 17 at South Street Seaport in Manhattan, with windows looking out at the East River. The name derives from “wayo secchu” — the blending of Japanese and Western styles — and on a recent Friday afternoon, a few weeks before the space opened to the public, the staff was working to dial in the concept. A dozen bartenders jiggled cocktail shakers rigged with laser pointers, trying to nail the figure-eight motion characteristic of Japanese mixology.