How to add more Reservation Point to Reserve Requisition Amount in the control budget

Summary:

We are currently using Oracle Fusion Procurement and Budgetary Control modules. By default, the system allows budget reservation (control budget check) on Purchase Requisitions (PR) only at two points: Upon Submit and Upon Approval.

However, our business requires more flexibility in determining when the PR amount is reserved against the control budget. Specifically, we would like to: Add new trigger points (reservation conditions) based on custom fields (DFFs) or custom process stages, where budget reservation should occur independently from Submit or Approval.

Manually or conditionally trigger budget reservation when specific conditions are met (e.g., a checkbox is selected, or a workflow reaches a defined step).