This may be by design, but when I launch a Notenik collection via a Link in another Collection, and that link is shortcut (e.g. notenik://open?shortcut=melville) it will open the collection, or if the collection is already open in another window, it will switch to that open window:
However, if the link is a file path, not a shortcut, it will open multiple windows of the collection (e.g. notenik://open?path=/Users/username/projects/project/collection-folder)
Which gets annoying when using a collection as a central project launcher.