It would be great if a tool could be created
This is helpful when you make notes and want to add something afterwards, but the space is not available. So you can select everything that is below the place where you want to add something and move the selection down. If the page runs out, the content is not lost, but is visible on the next page. If there is already content on the next page, a page is optimally inserted in between so that no content is lost. Analogously, the other direction would be optimal, in which you can push the text up if there is too much space in between.