copy and paste for a document
Please add a copy and past button for a document and a choice to either keep associated data or not. It would not require a duplication of images. If one deletes an image in a document, only the link to the image gets deleted (unless it is the last existing link to this image, when also the image itself should be deleted from the server).
To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information