Yes I am using the Dynamic Settings. I accidentally called it something else (Dynamic Scaling… d’oh!) in my above post.
That setting automatically lowers and raises your LOD to make sure you can hit your FPS target, so feel free to set your LOD settings to maximum. The Dynamic Settings will adjust your LOD lower for you automatically whenever your high LOD starts to reduce your FPS. Then it will raise them back up once you can handle the higher LOD again.
I used a tool to do this for me in 2020. Now it is built in.
It should reduce your Object LOD when you are at altitude (and can’t see the objects on ground) but boost it when near the ground FPS permitting, and it should raise your Terrain LOD at altitude when it doesn’t kill performance but lower it as you near ground or when your FPS suffers.
So if you are using Dynamic Settings, by all means set TLOD to 400 and OLOD to 200, and let the dynamic settings automatically adjust LOD lower when needed, and you will still get maximum LOD the rest of the time, or at least the maximum LOD your CPU can handle at your selected FPS target.