Jesus, that's a lot of music! (like my pun? lol) I'm not sure how to begin, so I'll just ramble for a bit. This will probably come across a little random, but hopefully you find some value in my thoughts.
So I listened to the whole thing, first of all. I really wanted to get your overall impression rather than dissecting this one movement at a time. I'm honestly glad I did it that way, because your piece is very programmatic which you stated. You constantly bring back themes or perhaps leitmotifs, which I thought was very fitting for the content.
After hearing it in its entirety, your piece fell victim to something I predicted when first hearing it. There's lots of sadness and despair to the theme, and even though there can be some moments of joy and redemption, I felt like it would be very hard to capture the mood for an hour of interesting music. Overall, it's a very constant grave/lento tempo throughout, and it was hard to keep interested at times. One thing you could maybe do to enhance the general shape of the music is to have a lot more sections of faster tempos, or maybe more sections with lots of movement in the textures. I know you give us moments of that (mvt. 2 cellos and violas, mvt. 3, but still a walking pace, mvt. 7 with the builds), but I don't think it was enough for an hour long piece. Even if the program element might not literally call for that, I think the music needs it.
You probably already know this, but the textures are very lacking. There are lots of tutti and block chords. I strongly encourage you when you begin orchestrating to constantly think of the overall texture. Really think about the instrument groups, the amount of color at your disposal, solo and duet passages, etc. I purposely don't want to give any thoughts on how I would orchestrate any of it, I think that would take away from the fun you'll have when doing so. Just be creative with it is all I mean. Even the several spots where you repeat a theme, really think about the different ways to execute that.
The registers were very consistently on the low end of things as well. Vary that up too! You can still paint the picture of a solemn atmosphere by really exploring the instrument ranges as well. I know this version isn't your final vision of the piece, but many of the bass parts could have been given to another cello part instead. Also the 2nd viola going to the violin. Yes you were going for that darker color, but, and especially with the bass, it really sounds muddy with the split parts.
You may not like this, but a suggestion I have for you is to nix the idea of the full orchestra and make this for string quartet or another chamber ensemble. For one, it would be much easier to finish a work you have written over the last several years, and you could really learn a ton by giving yourself the restriction in instrumentation to fully utilize the strings. There's a lot of articulations and technique for strings that you didn't use, and maybe it could be a cool opportunity to explore that. There's bowing, pizzicato, glissando, harmonics, and a gazillion other ways to give color for the strings that would be fun to try out.
HOWEVER...I know you're very passionate about the material, and this piece is probably very close to your heart, so I'm not saying don't orchestrate it. If that's your goal, that by all means go for it. I'd love to hear this orchestrated. I just would hate for you to spend so much time on a piece without venturing on to new music. You seem to really love orchestral music, so yeah man, do it if it's a major goal for you 🙂
Now, with all that said, I'd like to share some things I really liked about this. My favorite part is the theme at the end of mvt. 2 and brought back in mvt. 7. I love those chords, the harmony is very moving and speaks to my soul. Also, in mvt. 4, around 2:20 and done again later is a really cool section, I just wish it was longer!
Mvt. 5 was very cool, I loved the slow chords with the solo bass. Awesome sound, just make sure to add little bits of color, or texture, or movement over the chords, because after a while it tends to get stale. But the idea is very cool, reminds me of something Shostakovich would do. Mvt. 6 had some cool chromatic lines, I really liked that. Again though, think of ways to vary up either the color or the groupings as it wears on me after a while.
While I'm thinking of the timpani, also I'd think about what other percussive devices you could use in this. Just remember it's 2023, I'd take full advantage of exploring all of the different options you have in percussion as you go about orchestrating.
So in general, congratulations on creating such a behemoth work. I myself have never written anything that long, so kudos to you for being able to see this one through the end. Hopefully I didn't come off as too critical. Yes I feel like this needs a bit of work, especially in your pacing and textures, but I feel like you got the hard part out of the way. You already know all of your themes and harmonies, now you really get to have a lot of fun bringing this more to life by being creative in your orchestration. I'm very curious how this will turn out, definitely let me know once you're completely done if I happen to miss it.
Thanks again for sharing!