I made a list of the major text variations between 1977 Unwin paperback and 2021 HarperCollins Illustrated by Tolkien kindle edition https://docs.google.com/document/d/1BM ... UFGFPw9RNbs78NI5bmhIGe5Qw I notice some changes seem to be unmentioned in Reader’s Companion or elsewhere, so I don't know why they were changed. Could you help to check the 1st edition to see if they are the same? I've adopted the citation system on https://search.digitaltolkien.com/
I think three further changes might be considered for future LotR text. (I.8.89, II.8.82, D.12)

Prologue.36 when he lived still [> still lived] in the light

I.10.13 Please remember, said one of them, that the name of Baggins must not be mentioned. [EN: In I.8.89 there is “Please remember – all of you – that the name of Baggins must NOT be mentioned.”, In The Treason of Isengard the draft says “that the name Baggins must not be mentioned again”, perhaps the “of” in I.8.89 should be removed as well. It also fits the context better]

II.8.82 The long years have passed like swift draughts of the sweet mead in lofty halls beyond the West, [EN: Descriptive Bibliography 110 says “long” is an error induced in the 2nd edition. But it seems Tolkien added “long” on purpose to translate yéni. His translation in RGEO is “The long years have passed like swift draughts of the sweet mead in lofty halls beyond the West”.]

V.3.24 For what purpose they had made this place, as a town or secret temple or a tomb of kings, none [>none in Rohan] could say.

VI.1.11 He ran forward to the crown of the climbing path, and over it.

B.TA.7 and Celeborn took the [>all the] southern wood below the Narrows,

C. The underlines to Prisca & Minto in Baggins family tree, Esmeralda Took in Brandybuck family tree

D.12 The additional Litheday added [>was added] after Mid-year’s Day, and so the 184th day of the Leap-years was called Overlithe and was a day of special merrymaking. [EN: It seems the older version fits the context better.]