It would be super convenient to be able to convert a Single-Page Document into a Page and Move/Attach it to another Document. Use case: often I need to create a quick doc, or start brainstorming with the team, or a client calls and I don't have time to find the right document to create a new page - I create a new Doc, but regrettably, I don't have a way to then "attach" this newly created Doc to the proper location as a page, I have to open another window, find the right doc and copy/paste. Maybe I just didn't figure out the proper way to handle this process.