magento custom payment module for multishipping

Question

How can I enable custom module with redirect to a third party website after placing an order for multiple-shipping orders?

When I set protected $_canUseForMultishipping = true; customers don't get redirected for pay for the order.

Answer 1

Sorry, Magento does not allow redirection payments for multishipping orders.

The reason is, that Magento generates one order per shipping address, so the customer would need to get redirected to the payment page for each shipping address. That would be very annoying, so Magento denies that kind of payment.