We had problems with a Ukrainian refugee we helped because certified translations of her documents did not match. Her name was transliterated the German way in one place and the English way in another.

Those are translations coming from professionals who swore an oath. Don’t try to do it with code.

In the US, you can generally specify to your certified translators how you want proper names and place names written. I would suggest you or your friend talk to the translators again so that everything matches. It will also minimize future pains.

Also, USCIS usually has an "aliases" field on their forms, which would be a good place to put German government misspellings.