MoleUK

I have now moved from Windows 11 24H2, to Windows 11 23H2. It has fixed all issues. No CTD's, no freeze on coalition select, no huge freezes on server select menu. No lockups on main menu. The mission loads (to both MP and SP are now extremely fast, no hanging on terrain load or net sim post start for minutes at a time.
My DCS install, BIOS etc all remain the same as they were on 24H2. My overclocks/undervolts and XMP etc are all re-enabled, all SSD's and hardware is the same.
So, in my case it was the very latest version of 24H2 that was causing all the issues with DCS. Potentially it could have been a bad install, but given some of the issues other users are seeing I suspect 24H2 has some new problems with DCS that have appeared in the last month or two.
For now I will try and keep my system locked to 23H2.
^ See above mate.
While I can't say moving to 23H2 will solve all your problems, it did mine. Doing so does mean deleting everything on the windows drive, so it's not a trivial. And potentially you will need to prevent it from auto-updating back to 24H2.
Everything running great for me atm tho, will keep updating and reinstalling all my old software and see if the issue returns.

Unfortunately there are a LOT of potential causes for VR stutters. It's one of the most frustrating issues DCS has.
When you say the entire scenery, do you mean ONLY the scenery? Are the planes and everything else smooth in movement, but only the scenery jitters, as shown in the video here? If so, I have some suggestions you can try, they have worked to reduce or eliminate terrain stutter/jitter for some users but not all. Let me know.
 
As for more general stutter problems that don't appear the same as shown in the video: roll back nvidia drivers to 566.36 due to recent nvidia issues. Be sure to do a proper DDU process for that rollback.
Make sure mouse polling is at 125hz or less. This issue never entirely went away, and I think might have re-appeared for some users recently.
Make sure CPU core parking is disabled, and potentially you may want to disable low power states in BIOS.
Exclude the DCS install folder and savedgames folder from your antivirus.
Make sure programs that cause issues are either not installed or not running. MSI afterburner, iCue, armory crate, Nvidia app (the new one) and anything that monitors CPU usage can/will all cause issues with DCS. As can any program with overlays. Then there is also DCS specific stuff like tacview, and various mods that even when deleted can leave leftover files in various folders (the Loach AI gunner file in the hooks folder in particular).
If it's more like the terrain jitter shown in the video: Try using an external FPS cap and limit DCS to 71 frames (if running the headset at 72hz), I would suggest either nvidia control panel or RTSS. If that doesn't work, try running keeping that FPS cap and also using nvidia control panel to set DCS to vsync fast and low latency ultra. Let me know if it does anything, you may notice the FPS stats in DCS also start showing you as GPU limited when hitting your frame rate as well after those changes, rather than listing it as CPU render threat limited.
The terrain jitter problem is years old and actually isn't limited to just VR, it's just either a lot more prevalent or a lot more noticeable in VR. Or both. I have 0 experience in game dev or coding, but I assume it's something to do with poor frame pacing or a mismatch between the CPU thread handling terrain rendering and the others, but that's just a guess. But it might explain why external FPS caps seem to help alleviate it for some users, if not all.

Change your LOD switch from 0.1 to 1.0
Having it set to anything less than 1.0 will result in lower detail models appearing at short distances. And in some instances will make objects entirely disappear when they shouldn't, either due to missing LOD models or due to transitioning to a spotting dot when no more spotting dots are available.

I believe ED have said they have something coming that will stop you having to essentially redownload the entire map when it gets a small patch.
There's not too much you can do in the meantime, other than maybe splitting up the install across multiple drives.

Try setting the gunners to short. Long has occaisionally been broken in the past on the Huey and Mi-8.
Also, sometimes you do need to cycle the ROE if they get stuck as well.

I have a 5800X3D, the server list still overloads it and causes stutters/freezes as it lists them. It's the way it's always been, using the favorites tickbox is the workaround.

Gotta bring up the VD menu on the headset. Hold down menu button on left controller, go to stream settings and tick enable performance overlay.

https://www.digitalcombatsimulator.com/en/files/3328443/
Delete lines 87 and 88 as described. All those reflections will be gone.
This is universal, so effects every module to some extent. Fixes the shadows off lighting issues in the mi-8 as well.
Doesn't break IC or pure textures, so no conflict with MP.