How to Setup the Requisition Approval workflow deadline based upon specific approval Stages

We are implementing Project Manager Approval workflow while creating project based requisitions in Oracle fusion. We have a requirement for project based requisition where in case Project Manager doesn't approve the requisition, the approval workflow should trigger the next stage approval based upon DOA and Amount after 6 days following 2 reminders in 3 days of interval.

For Non project based requisition, there should not be any escalation/deadline triggering.

Currently we have defined a custom stage between HeaderPreapproval and Header stage such a way that the Custom Stage will be utilised for Project Managers approval related rules and Header stage has approval rules based upon DOA and Amount following Employee Supervisor hierarchy in such a way that as soon as project based requisition is submitted, the approval workflow will trigger the approval for Project Manager first, post approval it will go to next stage of approval (employee Supervisor hierarchy in serial)