How can we prevent automatic splitting of the order line and instead allow manual control to split

Split Order Scenario:
When creating a sales order, if the quantity entered for an item exceeds the available stock in the warehouse, the system automatically splits the order line into two parts for Make to Order item—one for the available quantity and another for the remaining quantity to be fulfilled later.
Requirement:
How can we prevent this automatic splitting of the order line and instead allow manual control based on the demand over when and how the order line is split?