I am using Translation by content directory. Do I need to completely copy the default content directory to the new language translation directory when translating a site? Or is there a way to link the missing files in the new directory from the default directory to avoid duplicating the content of untranslated pages. Similar to what is described in the Page Bundles documentation about images.
I suspect your current best approach would be to mount your default content directory multiple times with different languages. I remember @jmooring writing about this some moons ago.