I quick browsed the docs
Underside Terrain Mesh
Obviously disable any mods like DVLaSS Skyrim Underside, which was made by extracting this automatic generation from DynDOLOD into a mod.
So dvlass is an outdated mod and doesn't need to be used anymore, it can be completely replaced by the terrian underside option?
Or just no need of DVLaSS Skyrim Underside optional files, dvlass actually has its irreplaceable effect
TVDT - Occlusion Data
Generation
To enable generation of occlusion data, check the Occlusion data checkbox in the advanced options.
Plugin- check to generate a dedicated Occlusion.esp, which is equivalent to using xLODGen.
I actually checked the Occlusion Data and plugin options in the advanced options, but when the dyndolod finish generation, I did not get Occlusion.esp