Okay, let's look at that example. (Interesting that that is what you would choose to point to, given our previous discussion.)
It is unambiguously clear that LQ 42 is the source for this paragraph. That is not a question; I think even you would accept that. Looking at the material in HoMe, specifically Morgoth's Ring, we see that this chapter is printed in full. Some emendations are noted in the text itself. It is then followed by extensive commentary in which Christopher notes other emendations that were made, including some that were much smaller than this one. The commentary for this very paragraph states:
$42 The passage describing the White Lady of the Noldor was added on a slip to the original QS typescript, and this slip is a page from a used engagement calendar dated October 1951. At that stage her name was still Isfin. A rejected draft for this rider on the same slip began thus:
She was younger in the years of the Eldar than her brethren, for she awoke in Valinor [not upon Middle-earth )] after the making of the Silmarils, and even as the first shadow fell upon the Blessed Realm; and when she was grown to full stature...
The words 'She was younger in the years of the Eldar than her brethren, for she awoke in Valinor not upon Middle-earth' are not in accord with AAm, where Fingolfin their father was himself born in Aman ($81).
The rider was not taken up into LQ 1 as typed, which still had the name Isfin, as in AAm (see p. 102 notes 8 and 9: the first birth-date for Isfin (1469) makes her born after the making of the Silmarils in 1450, but the second (1362) before). But later Isfin was changed to frith on LQ 1 (at the same time as the corrections of Finrod to Finarphin, etc.), and the same rider was attached on a slip, identical in wording to that attached to the old QS typescript, but with the name frith. This is presumably a case where a 'lost' change was recovered.
In QS Angrod and Egnor were friends of the sons of Fëanor, while Inglor and Orodreth were friends of the sons of Fingolfin, Fingon and Turgon. Now the association of Angrod and Egnor with the Feanorians (which led to their being allowed passage in the ships at the time of the crossing to Middle-earth, QS $73) was abandoned (as it was also in AAm, $135, pp. 113, 125), and all four of Finarphin's sons become the bosom friends of Fingon and Turgon. 'And these four' was changed to 'And these three' on LQ 1 when Orodreth was finally ejected entirely from the third generation of the Noldorin princes (see III.91, 246, and Unfinished Tales p. 255 note 20).
Here Galadriel enters the Quenta tradition; for Galadriel in AAm see $$85, 135 and commentary. On one copy of LQ 2 my father noted: 'In High-elvish her name was Altarielle "Lady with garland of sunlight", galata-rig-elle = S[indarin] Galadriel. It was thus mere accident that her name resembled galad (Silvan galad tree ). Cf. the Appendix to The Silmarillion p. 360, entry kal-.
Given how complete this is, I think it is reasonable to assume that there is no variant LQ text that includes the removal of the "most valiant" language. Certainly there is no place in
Morgoth's Ring or any place else in HoMe that suggests that there is, or that the published
Silmarillion reflects a further state of development of LQ by Tolkien himself. On the contrary, his comments suggest otherwise. The only thing that I have ever seen that suggests that is the material that you posted yesterday that he sent you regarding his "report" on the sample that I had sent him, talking about how much more extensive his History of the Silmarillion was than HoMe. I reiterate again that none of that material was sent to me. Only the brief brief statement that that HoMe does not provide all of the massive manuscript material necessary to determine how the Silmarillion was constructed and that he doubted "that such a close, line by line manuscript comparison with no leavening commentary or conclusion would be of sufficient interest to merit publication." He therefore declined to lend his support to the project.
This is a very, very different example than the one that you pointed to from the Ainulindalë, that was in the sample that I sent to Christopher, and which I explicitly removed from the final version of
AR. In that case, the source text was not printed in full, and Christopher pointed out to you (but again NOT to me) that I was not justified in making an assumption about the source text based on what he had said about it.
I independently reached the same conclusion, and removed that point (and many others like it) from the book (along with abandoning the close line by line manuscript comparison and adding considerably more commentary and conclusion). In this example, we have a source text that is given in full, with extensive commentary about what comments and changes were made to it. If we can't rely on it being complete other than in the most minor of details, than I don't know what we can rely on.
But given how precise and clear Christopher is, I continue to feel confident that we can rely on it.
As for why I said that I think it is "odd" that Christopher did not explain this change, it is because I believe that it is a particularly significant one. If he had explained it, there would have been no need to speculate as to why it was done. And we wouldn't be having this discussion. It's true that HoMe was not meant to explain the reasons for the selections and changes made, but he did do so in a few circumstances. I wish that this had been one of them.
"Spirits in the shape of hawks and eagles flew ever to and from his halls; and their eyes could see to the depths of the seas, and pierce the hidden caverns beneath the world."