Custom wp-config.php

Hi,
We use a custon function.php and we have the following:

define( 'WP_CONTENT_DIR', dirname(__FILE__) . '/content' );
define( 'WP_CONTENT_URL', 'https://mydomain.co.uk/content' );
define( 'WP_PLUGIN_DIR', dirname(__FILE__) . '/content/add-ons' );
define( 'WP_PLUGIN_URL', 'https://mydomain.co.uk/content/add-ons' );
define( 'PLUGINDIR', dirname(__FILE__) . '/content/add-ons' )

define( ‘WP_CONTENT_DIR’, dirname(__FILE__) . ‘/content’ );

Could you please help us adapt your WordPress Safe Updates required configuration?
Here is what we managed so far but we are not sure able the ‘WP_PLUGIN_DIR’

function currheap() {
  return isset( $_COOKIE['_alt_heap'] ) && ! empty( $_COOKIE['_alt_heap'] ) ? preg_replace('/[^a-z0-9_]/', '', strtolower( $_COOKIE['_alt_heap'] ) ) : false;
}
defined( 'WP_CONTENT_DIR' ) || define( 'WP_CONTENT_DIR', dirname( __FILE__ ) . '/content' );
defined( 'WP_CONTENT_URL' ) || define( 'WP_CONTENT_URL', 'https://mydomain.co.uk.co.uk/content' );
if ( false !== currheap() ) {
  defined( 'WP_PLUGIN_DIR' ) || define( 'WP_PLUGIN_DIR', WP_CONTENT_DIR . '/plugins_tmp_' . currheap() );
  defined( 'WP_PLUGIN_URL' ) || define( 'WP_PLUGIN_URL', WP_CONTENT_URL . '/plugins_tmp_' . currheap() );
  defined( 'PLUGINDIR' ) || define( 'PLUGINDIR', 'wp-content/plugins_tmp_' . currheap() );
}

Thank you
Fred