Multiple Deposit on Invoices

Please create invoices which allow multiple deposits. Example: We have created an invoice for the full flat design fee, a retainer deposit was collected, and now only half is due to begin the concept and we can’t add a deposit request for this amount. It will only allow one deposit, which was the retainer. To keep it seamless, it would be great if we can add a few deposits: the retainer, half for concept, half for after the concept but currently we can’t. The only way around this is to have the retainer on a separate invoice which creates extra steps and confusion to the client.