Ability to add UI only fields calculated off of Sub-Queried rows

It would be great if you could add a UI only field to an object/field returned by a child query. The use case for us is to check whether or not the child object’s status matches the parent object’s status and highlight the child row conditionally. I can make a Salesforce formula field to check that, but I’d prefer to add this as  UI field instead of adding it to the data model.

On the same vein as this idea. Maybe they can be merged (if that’s a thing on the community?).