Around 1980, however, I discovered that a second, remixed version of HR was created by Mike for his 1976 4 LP Boxed release. 

It took me a while to like the second version, with it's enhanced and added vocals and various other changes in levels and instrument positioning, but I soon found that I liked them both equally well (who could not love the combined voices of Mike's sister, Sally, and Mellow Candle's Clodagh Simonds along with David Bedford's choir?)--that, though they are different--the first more flat, quiet, and uniform, the second more multi-dimensional and dynamic--I love them both for their unique expressions of Mike's temperament and maturation process. 

Yes! As a matter of fact, Mike so much preferred the 1976 quadraphonic mix that he formally stated that he wanted it for all future re-issues of the album. 

Both versions are available, however, on the 2010 CD re-release.

I was owner of the original 1974 version for years before I found out that there was another version. As I said in OP, it took me a while to "come to terms" with the remix but I have to admit, it did smooth out some of the rough spots from the original--and it brought forward (or in) the amazing vocals.

I'm reading this https://tubular.net/discography/HergestRidge" rel="nofollow - here :

tubular.net wrote: Despite his 1976 remix - which replaced the original mix on all subsequent LP pressings and all CDs - Mike seemingly remained unhappy with the mix of Hergest Ridge, leading to him remixing the album again in 2010. All CD releases now use the 2010 mix, though the Deluxe Edition also includes the original 1974 mix.

Listening to it now. It sounds good but I will have to listen to the 1974 and 1976 mixes to compare and listen for the seven differences... Still, I'm not really a fan of this album (I prefer the QE2 - Discovery album run...).

Thanks for that update! I didn't know this! Now I'll have to compare the 74, 76, and 2010 versions! (Which, because I LOVE this album so much, does not bother me in the least.)

So sad that Mike has never been happy with the album. I consider it one of the top four or five absolute masterpieces of pastoral, neo-mediæval prog--which is probably my absolute favorite style of music. (Give me Tellemann, Tallis, Palestrina, Vivaldi, Gregorian chant, Faun, Mediæval Bæbes, Corde Oblique, The amazing Blondel, Flairck, Five-Storey Ensemble, early Karda Estra, Geese and the Ghost, Principe di un giorno, or Hugsjá any day of the week!)

Boxed - more atmospheric and stripped down to the composition.

Original - more flowery maybe overproduced slightly.

Like both but prefer Boxed. Also that was the first version I owned.

In my opinion, this is the most whimsical and evocative version if you are seeking the pastoral sublime....

I'm so glad to see you mention Clodagh Simonds.  She gets overlooked way too often.  So much so, in fact, that even those few that know her from "Mellow Candle" don't even know she has a new band called "Fovea Hex" and has put out some high quality music, sort of a folk/electronic hybrid which is quite amazing.  That project is listed on this site, by the way....   http://www.progarchives.com/artist.asp?id=8950" rel="nofollow - FOVEA HEX discography and reviews (progarchives.com)   I highly recommend listening to the album "Here is Where We Used to Sing".  

https://foveahex.bandcamp.com/album/here-is-where-we-used-to-sing" rel="nofollow - Here Is Where We Used To Sing | Fovea Hex (bandcamp.com)

Thanks, Mike! I'd forgetten about Fovea Hex. I'm listening to them (from your bandcamp link) as I write this and am, once again, reminded of the unique beauty of that voice. Quite similar to a modern day favorite of mine, Julia Holter.

I've not heard of this but am not surprised that such a thing exists. Oh! to have been able to see that tour!