Read here about libraries, how they work, how they are loaded and what different types to load (non-included into addons: Best! Included into addons: Either with their own txt file: 2nd BEST, or without an txt file hardcoded from the addon's main folder txt file: Very much troubling as always loaded even if old and broken! Do not use this anymore if not explicitly needed by that library -> and 99% do not need this. CustomTitles does not provide an own txt file so it will need these hardcoded calls. So you need to update the versions in your subfolders to use the newest one, which you need to download then and overwrite in your subfolders of your addons where it is used).
https://wiki.esoui.com/Libraries
Basically libs load by the ingame addon manager once with the newest version IF they provide their own txt file.
If they do not provide a txt file they will be loaded like other addons from the main txt file of the addon, where the lua/xml files of the lib are named hard-coded. This most likely will make your addons fail and error as the files are ALWAYS loaded (no matter how old they are).
LibStub was the old obsolete way to load only the newest version of a lib. But it loads all older versions given as well, only overwrites them with newer ones.
So the current best way is to use the txt files, AddOnVersion and IsLibrary attributes to load only 1 version (the newest). And maybe update my libs to get a txt file.
Btw load times will not decrease significantly if you remove some of the files. The savedvariables, especially big ones, are the load time increasers.