We just would need to patch the dism provider dll. - thats why i search for someone who has some minor IDA reverse engineer skills.
Here's a complete Russian LP. Works perfectly. pcportal.org.ru/forum/60-5861-1 Just a heads up, after installing a custom language pack (like the above) your Windows 10 installation will lose the ability to update to the latest public build. To update to the latest official build you will need to uninstall your custom language pack.