Stupid simple conditional config for local and production w/ constants.

1-wp-config.php

<?php
/**
 * The base configuration for WordPress
 *
 * The wp-config.php creation script uses this file during the
 * installation. You don't have to use the web site, you can
 * copy this file to "wp-config.php" and fill in the values.
 *
 * This file contains the following configurations:
 *
 * * MySQL settings
 * * Secret keys
 * * Database table prefix
 * * ABSPATH
 *
 * @link https://codex.wordpress.org/Editing_wp-config.php
 *
 * @package WordPress
 */
 
define( 'WP_LOCAL_DEV', true ); // use this throughout if you have special "local-only" code. 

define( 'SUNRISE', 'on' );

// ** MySQL settings - You can get this info from your web host ** //

if ( WP_LOCAL_DEV == true ) {
    
    include( dirname( __FILE__ ) . '/local-config.php' );
    define('WP_DEBUG', true);
    define('WP_DEBUG_LOG', true);

} else {

    define( 'WP_DEBUG', false );

    // ** MySQL settings - You can get this info from your web host ** //

    define( 'DB_NAME', '{$my_database}' );
    define( 'DB_USER', '{$db_user}' );
    define( 'DB_HOST', 'localhost' );
    define( 'DB_PASSWORD', '{$password}' );

    // ** Domain and Location settings **//

    define('DOMAIN_CURRENT_SITE', 'mydomain.com');
    define('WP_HOME','http://mydomain.com');
    define('WP_SITEURL','http://mydomain.com');

}

/** Global database settings **/

define( 'DB_CHARSET', 'utf8mb4' );
define( 'DB_COLLATE', '' );

/** Global WP Configuration settings **/ 

define('MULTISITE', true);
define('SUBDOMAIN_INSTALL', true);

/** Global location settings **/ 

define('PATH_CURRENT_SITE', '/');
define('SITE_ID_CURRENT_SITE', 1);
define('BLOG_ID_CURRENT_SITE', 1);

/** WordPress Database Table prefix. **/

$table_prefix = 'wp_';
  
/* That's all, stop editing! Happy blogging. */
/** Absolute path to the WordPress directory. */

if ( !defined('ABSPATH') )
    define('ABSPATH', dirname(__FILE__) . '/');

/** Sets up WordPress vars and included files. */

require_once(ABSPATH . 'wp-settings.php');

2-local-config.php

<?php
/**
 * The base configuration for WordPress
 *
 * Configuration settings specific to a local installation of this WordPress package.*/

// ** MySQL settings - You can get this info from your web host ** //

define( 'DB_NAME', '{$my_local_database}' );
define( 'DB_USER', '{$db_user}' );
define( 'DB_PASSWORD', '{$password}' );
define( 'DB_HOST', '127.0.0.1' );

// ** Domain and Location settings **//

define('DOMAIN_CURRENT_SITE', 'mydomain.locdev'); // these should reflect your virtualhost settings
define('WP_HOME','http://mydomain.locdev');
define('WP_SITEURL','http://mydomain.locdev');

Nice work around, i like it 😁