Hi,

By choosing the Never option, the remaining quantities will be canceled without creating a backorder.

Please refer to the blog given below:
https://www.cybrosys.com/blog/an-overview-of-automatic-backorders-using-odoo-16-inventory-app#:~:text=A%20backorder%20in%20Odoo%2016,backorder%20for%20the%20remaining%20products.

Hope it helps

I'm afraid there isn't any setting or module to do so.. The traditional way is never confirm any sales order until you sure about the quantity that available for the transaction..This will prevent OpenERP to automatically create delivery order.. Just keep it at draft, so you can edit and confirm the SO any time you like...