The expert mode adds a few additional features to the advanced mode.
To start DynDOLOD in expert mode, use a text editor to set Expert=1 in ..\DynDOLOD\Edit Scripts\DynDOLOD\DynDOLOD_[GAME MODE].ini.
It is possible to change certain settings in the header of the export file to test different settings for example.
The button Rebuild Atlas updates the object LOD and tree LOD atlas textures depending on the Generate object LOD and Generate tree LOD checkboxes for the selected worldspaces based on the atlas map files of the last LOD generation process.
If any of the used textures has a different resolution, the positions of textures on the atlas will change - which will be rather obvious in the game. Update the object LOD meshes after rebuilding the atlas textures by clicking the Execute LODGen button.
The button Create Mod switches to the create mod mode.