unknownBlockStyle is not working / does nothing

The component override unknownBlockStyle is not working. It seems that when you provide a block component override, it is merged with the default block-styles, so that there never is an "unknown" block.
For instance if you define

  block: {
    // Ex. 1: customizing common block types
    h1: ({children}) => <h1 className="text-2xl">{children}</h1>,
    blockquote: ({children}) => <blockquote className="border-l-purple-500">{children}</blockquote>,
  },
  unknownBlockStyle: ({children}) => <BlockWrapper>{children}</BlockWrapper>,
}

the block style 'normal' should render with BlockWrapper, but instead gets render with the default component (<p>)

Start by reproducing the supplied components example with a block style of "normal", then trace the component override handling for block styles and unknownBlockStyle. Done means the normal block style uses the provided BlockWrapper instead of the default paragraph component, with a regression test covering the example.