No, but it is non-transparent and can’t be edited with a text editor, without being unpacked and repacked like Fossil. Yet another layer of indirection is the last thing I want when I’m in a hurry to write down a thought before I forget it. Of course that can be overcome with practicing the tooling, but that’s also a non-negligible transition cost.

Yes, because the database is the custom schema + the data being managed by the library, not the library itself.

The library is properly an example of a DBMS: database management system, it's only "a database" informally to lay users.