I edited my usercfg.opt file as suggested by others to make the TERRAIN and OBJECT LODfactors be 4.0 instead of the default 2.0 (also for VR from 1.0 to 2.0 for both). MSI Afterburner and Windows Game Bar both say that I’m using about 16 Gb of RAM out of a 32 Gb total with ~all ULTRA settings. It’s worth it! The level of detail has definitely increased over the default ULTRA settings, both in 2D and VR, although VR is not without a few microstutters here and there. I’m running at 100 TAA render, 200 LOD in MSFS graphics settings for both TERRAIN and OBJECT LOD, OXR custom scaling unchecked (let app decide) with motion reprojection always on. Following in the footsteps of others on the forum the 2D view is fabulous, the VR sharpness greatly improved at the price of smoothness.
Edit_Update: Should add this is with the new precache slider on ULTRA, too, in MSFS graphics settings.