Project Settings asset is a project wide settings that keeps reference to default Database and Manager. It can be accessed in Edit/Project Settings.../KNOT Localization.
On application startup (After Loading Assemblies), if Default Database is assigned and Load on Startup is enabled, KnotLocalization will pass Default Database to Manager and forces to load startup language.
Reset User Settings clears current user related data like Current Active Database, expanded items in Database Editor and so on. This will not affect any project settings or assets data.