Is it possible to edit fluent.conf to create a custom format for application logs in OpenShift 4?

Issue

• Openshift Logging collects application logs and forwards them to a security information and event management (SIEM) application that expects a custom header format.
• Can the fluent.conf be edited in the ConfigMap to add record_transformer lines that insert the desired headers into the forwarded logs?
• Will fluent.conf edits persist or will the operator/audit function replace the edits with the factory defaults?
• Does Openshift Logging operator allow to edit fluent.conf to add extra information?