Stop stock allocation during STO creation

Hi Experts

Issue:
Stock Transfer Order (UB STO) created with a long leadtime (delivery date = 4 months ahead) are allocating stock and
preventing some sales orders to be shipped.
Business needs to remove, manually, the stock from the STO orders to release the inventory and prioritize the sales orders.

Requirement:

- Stop stock allocation for these STOs with long leadtime

- The stock should be allocated and confirmed only during the delivery creation for the STO (VL10B)

Could you please advise on a solution for this issue?

Thank you,