Adds support for post excerpt and WordPress SEO meta fields to alternate versions

bu-versions-wp-seo.php

<?php
/*
Plugin Name: BU Versions - WordPress SEO Support
Description: Adds support for post excerpt and WordPress SEO meta fields to alternate versions
 */

/**
 * Required as the WordPress SEO plugin doesn't use post type support, and BU Versions requires it.
 */
function wpseo_feature_support() {
	add_post_type_support( 'page', 'wpseo' );
	add_post_type_support( 'post', 'wpseo' );
}

/**
 * Register WordPress SEO meta keys for alternate versions.
 */
function wpseo_alt_version_features( $features ) {
	$features['wpseo'] = array(
		'_yoast_wpseo_snippetpreview',
		'_yoast_wpseo_focuskw',
		'_yoast_wpseo_title',
		'_yoast_wpseo_metadesc',
		'_yoast_wpseo_metakeywords'
	);
	return $features;
}

/**
 * Add "excerpts" to the alternate version post type registration arguments.
 */
function wpseo_alt_version_args( $args, $post_type ) {
	if ( post_type_supports( $post_type->name, 'excerpt' ) ) {
		$args['supports'] = array_unique( array_merge( $args['supports'], array( 'excerpt' ) ) );
	}
	return $args;
}

add_action( 'init', 'wpseo_feature_support' );
add_filter( 'bu_alt_versions_feature_support', 'wpseo_alt_version_features' );
add_filter( 'bu_alt_version_args', 'wpseo_alt_version_args', 10, 2 );