I guess I should have been more explicit:

Adding code to `wp core install-network` that can work only if you add the above incantation to your `wp-config.php` file is not acceptable.

You could at least hide part of chaos:

```php
if ( function_exists( 'WP_CLI\\Utils\\about_to_install_network' ) ) && WP_CLI\Utils\about_to_install_network() )
```

Or, ideally, find a way to not have to change `wp-config.php` at all.

PS: Given `wp_config_contains()`, are you sure it's still needed?