To customize the global configuration files (files in /etc/) that belong to Nginx, Apache, or PHP, you can use the following instructions:
If you follow the above instructions, you won't risk ServerPilot overwriting your changes and you'll continue receiving automatic updates for PHP, Nginx, and Apache.
If you customize a file, ServerPilot will no longer be able to update that file. Therefore, it's better to add files to an app's configuration directory (as described in the above documents) than to rename configuration files to *.custom.conf.