Often, I want to write on one page or section of a document while viewing the same document in another window. Or I want to open my two-page guitar score (in one document) in two separate windows to have the score fitted perfectly on the screen of my iPad in landscape mode.
Currently, I have to open another GoodNotes window and find the document, which can often take a while. It would be so much more efficient if I could just open the same document in a new window directly via a new button.