Redirect Yoast attachments redirects to Optimole urls.

optimole-tweak.php

<?php
/*
 * Plugin Name: Optimole Tweak - Redirect Yoast attachments to Optimole urls. 
 * Version: 0.0.1 
*/
add_filter( 'wpseo_attachment_redirect_url', function ( $url ) {
	return apply_filters( 'optml_content_url', $url );
}, 999 );

add_filter( 'attachment_link', function ( $url, $id ) {
	if ( is_admin() ) {
		return $url;
	}

	return wp_get_attachment_image_url( $id, 'full' );
}, 999, 2 );