I've been banging my head against this for a couple weeks now, I've read I don't know how many threads, tutorials, and guides here and other places about similar issues, and I'm at a loss at this point. It's been years since I've been able to do a playthrough of Oblivion because it is so prone to crashing, I've tried this twice before and quit out of frustration over this issue.
For the most part everything is perfect. In interior cells I have absolutely no problems, everything runs smoothly. When I go outside the performance is still decent, but when I walk through certain areas the game will freeze for a second or two before crashing to the desktop. Specifically, the stone circle with the pillar in the center just outside the Vilverin entrance has been pretty consistent about it, if I go near the pillar it will crash, but there are also several places where it happens less consistently along the Talos bridge and the trail leading up to it from the south on the Imperial Isle side. That's as far as I made it before I stopped trying to play and started testing.
I have found that if I disable archive invalidation (i.e. most mod textures/meshes/etc. don't load) it doesn't crash, but I have tried disabling and enabling (in Mod Organizer, so the textures/meshes/other files aren't present at all) just about every combination of mods in my list and nothing seems to fix it except disabling archive invalidation completely. Even with just the unofficial patches it will crash (and even with them disabled, but others enabled). I have also tried tweaking the graphics settings, as low as 1080p, no distant land, no AA, with the original settings being 4k, distant land, max settings for everything. I have a Ryzen 7 3700X, 32GB DDR4, and a GTX 1080Ti, and all storage is on SSDs so I can't possibly imagine that the hardware isn't up to the task. I have also watched the resource usage in Task Manager and as far as I can tell there is no noticeable spike or pattern in RAM, CPU, GPU, or disk usage that precedes the crash.
I have tweaked settings in OSR and I also have MoreHeap (because enabling heap replacement in OSR causes the game to fail to start entirely) with heap size set to 1000. I've also used the 4GB patcher, first on just the executable and OBSE and then on every exe and dll I could find that was being loaded by the game. I am using Mod Organizer 2 for everything except MoreHeap, ENB, OBSE, and another OBSE plugin I grabbed to log engine messages. I have also tried deleting and recreating INIs with no success.
Mod List (order inverted for some reason):
LOOT is used for load order. Any plugins preceded by asterisks are not actually activated, but are included in the bashed patch. Also, I have used TES4Edit in QuickAutoClean mode to clean all plugins as much as possible, except for the unofficial patch which says to leave ITMs in LOOT.
As I mentioned earlier I also have a plugin to get engine message logs but there's nothing in there that obviously indicates a problem. The end of the log is usually filled with things like:
"Trait defined outside of any tile."
"Attempting to play 2 channel sound <WAV_FILE> in 3D (must be mono)" (WAV_FILE is usually a sound file from Sounds of Cyrodil)
"AddItem in script 'salWallaceVeyInventory' failed to generate an item."
"Disabling collision on ref '<Arrow1Iron>' (<some_ref_id>)"
All warnings, not errors. The only one that's been consistently present regardless of which mods are loaded is the first one, but it's present throughout the logs start to finish so I don't think it's related to the crashing. For reference, before I used the 4GB patcher I would get an out of memory error at the end of the log which clearly indicated what the problem was.
Just earlier today I thought I might have it all fixed (after uninstalling/reinstalling, redoing the bashed patch, clearing INIs, reading through forums and readmes and making a few tweaks, and adding OSR and MoreHeap) so I started a new character, and everything was going perfectly until I reached that spot outside of Vilverin where it crashed again, exactly where it had with the previous character. I'm completely at a loss at this point, any help would be much appreciated.