Does every GN4 customer has "own" directory styles?
The answer is Yes!
Ofter, customers require a small change in the configuration. Even for the smallest change, you need to create a copy of the entire CONFIG folder and all subfolders, and do your changes there, and not on the originally downloaded files.
Why is that so?
That's so because you will need sometimes to reload some standard configuration files, because of Tera-related changes to be applied to your system. Should you download and expand the standard configuration files in the same set of folders where you made your custom changes, your changes will be lost.
Conclusion: edit, add, rename, or delete entry dialog boxes in your copy of the configuration files and not in the standard set of the configuration files. It is recommended to keep your custom files in the SVN repository. See Using SVN as source control.
See also
Does every GN4 version has "own" directory styles?