Adjust the Postgres ODBC driver to query user access permissions and render ONLY the schema & tables the user can really access. There are examples online of how to get this list instead of pulling the full database, schema & table list.
This would then clear ugliness of the current driver when used against a secure platform. See PowerBI for how much better its driver works with Postgres, compared to yours in Excel when a database has restricted permissions that allow only access to some tables.