Unfortunately, port constraints are only considered if the layout style is set to "Directed" (but even there, they don't have an impact on the node placement). Furthermore, the horizontal-vertical layout doesn't support a "from-sketch" -mode that allows to specify a vertical node order (which I guess is important for your use case). I recommend to repost this as a feature request because such a layout style seems to be useful to visualize hierarchical structures like, e.g., sections/subsections of a book.
