Enforce domain mapping mapped domain for all front-end urls ran through esc_url()

frontend-force-mapped-domain.php

add_filter( 'clean_url', 'sav_force_mapped_url' );
function sav_force_mapped_url( $url ) {
		if ( ! is_admin() ) {
				if ( function_exists( 'get_original_url' ) && strpos( '/wp-admin', $url ) === false ) {
					$original = preg_replace( '#^https?://#', '', get_original_url('') );
					$new = preg_replace( '#^https?://#', '', site_url() );
					$url = str_ireplace( $original, $new, $url );
				}
		}
		return $url;
}