Sorry for the rez, but this was a top result on google when I searched so will likely become relevant for others in the future. I want to summarize my understanding of everything so far to ensure I'm getting it all right, and give an opportunity for this thread to be updated if anything has changed.
1. The current version of DynDOLOD (2.43 at time of writing) hides BSheartland (Beyond Skyrim Bruma's worldspace) entirely so LODs can't be generated for it. If you want to generate LODs for this worldspace you'll need to remove the BSHeartland entry in DynDOLOD\Edit Scripts\DynDOLOD\DynDOLOD_[GAMEMODE]_worldspace_ignore.txt.
2. If you decide to generate LOD for BSheartland (bruma) you can run DynDOLOD twice and merge the results or delete the .bto files for bruma. More detailed instructions in post #2
3. We can ignore all of this and just generate all LODs like we would normally for all world spaces including Bruma, but some objects will be missing in the distance.
4. https://www.nexusmod...ion/mods/11010/ claims to partially fix #3 above by adding the imperial city whitegold tower back into LOD and the map.
Where I'm still confused is, is that linked mod enough? Is there a sufficiently distracting lack of LOD still in this worldspace or was that really the only thing anyone was bothered by? Also, if I ignore bruma and don't generate treelod for it at all isn't it going to be hideous, or does it use all it's own custom trees with prebaked lod? I've never actually played in that worldspace yet despite all my hours in this game .
Edited by Drexl, 24 August 2018 - 05:43 PM.