add mediaelement.js plugins into WordPress video player control bar

You can alter the mediaelement.js feature-set using the mejs_settings hook. Settings Overview

Defaults are: playpause, current, progress, duration, tracks, volume, fullscreen.

Add the plugin to the array as needed to extend the features.

add_filter('mejs_settings', function ($settings) {
$settings['features'] = array(...,'jumpforward');
    return $settings;
});

Make sure to enqueue the plugin itself:

wp_enqueue_script( 'mejs-plugin-name', 'path_to_plugin_file', array('wp-mediaelement'), null, true );