The fact that it was definitely not "Jehovah" is already known from the fact that there is no /dʒ/ sound in Hebrew. Whether it could have been "Yehovah" is also not represented by any serious researcher or Hebraist, this is as marginal and exotic an opinion as the Flat Earth Society exists. As far as it is at all possible to establish certainty in such a case, it is the Yahweh version.
The fact that it was definitely not "Jehovah" is already known from the fact that there is no /dʒ/ sound in Hebrew. Whether it could have been "Yehovah" is also not represented by any serious researcher or Hebraist, this is as marginal and exotic an opinion as the Flat Earth Society exists. As far as it is at all possible to establish certainty in such a case, it is the Yahweh version.
There was no appreciable argument in any edition of the NWT that even remotely reached the concept of "clear and compelling evidence". I would like to draw your attention to the fact that you specifically call ALL New Testament text copyists Bible forgers, and in this regard you bear the burden of proof. To prove this "beyond a reasonable doubt" (to use a courtroom term), do you think this wishful speculation that it is "reasonable to assume" "couldn't be otherwise" would pass in a courtroom?!
The existence of autographs is not "helpful", but the only acceptable evidence itself, on the basis of which we establish the text. Because if the thousands of copies of the text were falsified in the sense that "Jehovah" was taken out, with this logic, how do you know how many other aspects were falsified? With this, you kick the chair out from under complete Christianity.
The fact that it was included thousands of times in the Old Testament does not at all follow from the fact that it had to be included in the New Testament as well. That's about as much reasoning as saying, "Since my bathroom has a sink, it follows that my living room also must have a sink." It is not as if the burden of proof is on me in this regard, and I should explain why if it was included in the OT, why not in the NT, but I will help:
Maybe because the theological environment has changed? Maybe because it was no longer needed? Because Yahweh himself was just a reminder to the Israelites, who were still leaning towards polytheism, to remember that there is only God "Who I am" (thus who truly exists)?
Otherwise, the Tetragrammaton does not appear in the Ecclesiastes, the Book of Esther, and the Song of Songs. Couldn't it have been there as well, only the "apostate" copyists removed it, and should it be "restored" in the NWT? After all, with your logic, it's impossible that if it's in one book, it can't not be in the other.
I note that if God had an objection to this, why didn't He send a Jeremiah-like prophet in the intertestamental age to rebuke the Israelites for not saying the name YHWH? Why didn't Jesus concretely criticized this practice by a single word? And the apostles? Or maybe this has no significance for salvation?
"The fact of a quotation has the NAME then it would be expected that the NT author or copyist would faithfully reproduce that name in the NT quotation"
So "it would be expected"? By whom? I translate: "Since I cannot imagine that the writers of the New Testament did not approach this question as it should be based on the logic of my denomination, so it had to be this way". "We know that they were "apostates" from the fact that they omitted the name, since if they had not been apostates, they would not have been taken out." This is also known as circular reasoning.
"and there is sufficient evidence in the absence of the autographs that this was the practice.
And what would it be? Do you have such a manuscript? Is there an author who specifically reports seeing a New Testament manuscript containing the Tetragrammaton?
As I see, you failed to answer my suggestion that the basis of the hypothesis is that the Tetragrammaton was included in SOME (probably archaizing) editions of the Septuagint, but how? Writing YHWH in the Greek text with Greek letters and vowels? No, but Hebrew letters, without vowels, right in the middle of the Greek text. Well, what the NWT does is not to put "יהוה" in the English text, but to write it in Latin letters, according to English phonetics, as "Jehovah". However, no one had ever done this in a Bible translation before the modern era. Both Howard and Stafford argue that these Old Testament quotations were not written in the New Testament in Greek letters, with Greek phonetics (e.g. Γιαχβέ), but at most in Hebrew letters as "יהוה". Come on, by not acting like that, you even went beyond your own - I emphasize again: unproven - hypotheses.
Before modern times, Jews did not translate the Tanakh into vernacular languages, but used the Hebrew text in their worship. Of course they knew YHWH, they just didn't say it. In the Christian era, this question did not arise, neither positive nor negative, they simply readily adopted the custom of the Jews, which, as I emphasized: no one objected to in the New Testament. The name in which we are baptized is Father, Son and Holy Spirit. The name Yahweh has no significance for salvation in the New Testament. Regardless, it was never "obscured".
And if you call yourself a "scholar", then show an attitude a little closer to the so-called scientific methodology, instead of sweeping away the arguments of the debate partner with the terms "lengthy, boring" and "Franz's nonsense".