According to the described, I can recommend that you make the same orders to the supplier, while creating new products based on fictitious ones (goods can be loaded from the order through a special block, the action on the procedure is to create from fictitious ones - real ones), and then in the order itself, indicate when the delivery should be. , waybill, etc.
For a more accurate development of a business process, I would recommend you the services of integrators
https://crm-onebox.com/ru/integrators/ - they will be able to more accurately draw up the terms of reference for the functionality you need.
Or if you have a personal technical support manager - check with him about the possibility of solving your problem.