Allow highlights to be created in ANY rich text field, not requiring entity to be of Source database

Currently, the Highlight feature mandates that the entity containing the rich text field is part of a Source database. This setup restricts the flexibility of where highlights can be applied. The Highlight configuration has a limit of source databases.

Would it be possible to allow highlights to have either have a ‘default’ source database, not just the one inherently associated with the current entity? Or, that the source database is not present at all?

Could this be achieved by adding explicit sourceTypeId and/or targetTypeId attributes in the Highlight configuration within the JSON structure?

The idea is that the Highlights feature could be more universally used in rich text fields.