Not sure how difficult this would be to implement but.
For the CMS/Pages application: The ability to choose different schema types for different databases and pages, such as an about page, using to json-ld generator.
Also since different schema types have different properties, the ability to match/ choose schema properties with custom field types.
This is similar to how yoast works.
I'm not sure if this is fully possible with the Google data layer but that seems a bit complicated to implement.