I have posted in the Illustrator group but as it is linked to Indesign I am posting here as well.
Context: I have to modify an InDesign document created by an advanced graphic designer. He has created images in an Illustrator source file that are linked in Indesign, meaning that from Indesign I can edit the original image directly in Illustrator. I need to translate this document into a 2nd language, so I want to duplicate the document (to avoid redoing everything) and modify these images.
Problem: how to duplicate the images of the source file illustrator so that they are automatically modified in the InDesign document?
I don't know if this makes sense or if I'm complicating everything for nothing, otherwise I'd be happy to provide you with the necessary clarifications.
When you modify the original illustration in Illustrator it will trigger a moidified link warnign in any InDesign document where it was placed and you can simply update the link at that time if the document is open, or on the next opening.
Package the document (File > Package). That creates copies of the document itself and all linked assests in a location you choose. Execute the translation work on the packaged copies, and the original, primary-language document and assets will remain where and as they are.