Workforce Health and Safety Incidents - security role for Event Owner, Investigation Owner etc

Summary:

How to create security roles for Event Owner, Investigation Owner etc in Workforce Health and Safety Incidents?

Content (required):

Has anyone created a version of the Environmental Health and Safety (EHS) Manager role so that, for example, an Investigation Owner can view and update investigations that are assigned to them? I have successfully created a role for the Incident Owner based on responses to a previous question here but cannot work out how to give access to an Investigation Owner unless they are also the Incident Owner.

Any whitepapers or tips on how security is configured in Workforce Health and Safety Incidents?