Is there a way to configure subscription service parameters to be filled in during a renewal order, or amendable after subscription is provisioned?
Service Parameters are offered to customers during initial subscription purchase if the parameter is set to "Ask on Order Placement". Furthermore those service parameters are non editable once subscription has been provisioned.
It is not possible to ask customers to fill in Service Parameters in Renewal Orders in current version of PBA. Service Parameters are asked on Order Placement during initial purchasing of Subscription and do not store in subscription in PBA (it is stored in details of Provisioning Items) because they are designed to pass required details to external systems.
There is a Feature Request created to implement this functionality in PBA, Feature Request ID PBA-55528.