How to extend OrderItemUnit model to prevent making entries into order_item_unit table for individual unit

Hi, one of our client having requirement to allow customer to order product quantities more then 9999. But when he tried to do that, he is facing time out issue because the sylius is making an entry of every unit separately in order_item_unit table.

Is there any way we can extend the core file and prevent the sylius to making entry in order_item_table and only calculate the data from order_item table only?

This way the execution time will be minimal and we can prevent the unwanted data store into the db.

Thank you in advance!