For example, I have Lost Library and it does not have them and needs to be added manually.
It should automatically fetch mods that have 'bash tags', but not every mod has them. Just install and open Wrye Bash and create a patch, opt to skip merging mods unless you're sure that's what you want to do and hit the 'leveled lists' section. I don't understand exactly how that all works yet, as some mods definitely show up without merging their leveled lists, but it's a reasonable thing to do if you have a bunch of equipment mods and want to make sure said equipment shows up in the hands of enemies, in chests and available for sale from merchants. Click to expand.It's a mod organizer like all the others but it has a functionality called 'bashed patch' which can combine simpler mods or, what you've heard, the 'leveled lists' included in said mods.