I have a localized storyboard file the old way (no use of "Base Internationalization"):
I changed the first file by adding a new ViewController. Now I realized, that these changes don't effect the other (localized) storyboard files.
How can I edit all the storyboard files at once?
You don't. You have to change each file individually. That's why Apple created "Base Internationalization."
I used to deal with an OS X app with 23 translations and many nib files. Here's how the process looked prior to Base Internationalization:
It's not pretty. Again, that's why we have Base Internationalization. Now may be a good time to move over.