In TinyMCE, it was possible to customize the paragraph styles dropdown by adding some configuration to the "editor_tinymce | customconfig" setting like:

{

    "theme_advanced_blockformats": "p,h3,h4,h5,h6,blockquote,code"

}

I would love to see such a possibility in atto, too, as it would open possibilities to use standard HTML tags like blockquote for formatting and styling.