Assets read only custom field public doc is misleading:
read only insight custom field

At the moment the doc does not specify that:

• The read only custom field will populate according to the IQL set in the Filter Assign Scope. The relationship to another custom field or any Jira issue placeholder should be indicated here.
• The Insight read only custom field will only populate update upon an Issue Created / Issue Updated event in Jira. Updating the Parent custom field in the Issue view, or using a Generic Event in a Postfunction Transition, will not trigger the read only custom field to populate / update. (this also applies to the Filter Assign Scope Strict in the Object default CF)

Also the included screenshot does not show the Filter Assign Scope filled, confusing the customer about the field purpose.