It would be great to have the ability to create blog posts translations through the API as this would allow to migrate blog content programatically.
In fact, the new/beta API actually documents the necessary fields as if they were available for use. This make matters worse as it gives developers the impression that the feature should be easily available.
Thank you for this feedback! I am excited to share that we have made an update and you can now create language variations via the API. Here is a reference doc and below is a screenshot.