Quendi,
While I will support your position that the name "Jehovah" was published in some form as early as the 12th century, I stand by my initial statement:
==> "Jehovah" is the English version of the Greek version of the Hebrew version of the YHVH with added vowels <==
Yes, of course other languages use their own variations on the name Jehovah. I wasn't talking about German, or French, or Spanish or Swahili. That goes without saying.
There is no evidence of Jesus, while surrounded by his followers, commanding or even suggesting that they call the Father "Jehovah." Nor is it likely that he told them to call Him "Yahweh," although that is more likely than "Jehovah."
I still hold my position that there is no evidence that the name JEHOVAH has any particular significance or any higher accuracy than any other name for God Almighty that some cult wants to pull out of their ass.
JV