There should be no need to add a separate field to the plugins database.
Any plugin which implements the Privacy API must already declare that:
- they store personal data in a database table;
- that they make use of various Moodle subsystems, and plugintypes; and
- that that they export data to an external system.
We should be able to interrogate each plugin in the database to display this kind of information without adding a new field in the database itself.