Not currently. That would require some code change. Will ‘Portfolio Home’ page work for you? You can have content on the top with the help of Custom Heading Content markup in the metabox provided below the page editor. You can insert any number of segments into this field. Then the portfolio items would show up and rest of the content (additional segments) can be input in the regular TinyMCE page editor of WordPress. Not very flexible but gets the job done.
Let me know if you this seems cumbersome and I can probably get a custom shortcode written to take care of this. I suspect it would require just a little bit of custom styling.