Custom dev request: make flowcharts showing connections between people, companies, projects

Hello. Currently the plugin displays a hierarchical chart of employees who have registered user accounts on the website.

I would like to use a modified version of the plugin capable of displaying relationships between individuals, companies and projects, and possibly other taxonomies and categories that the user creates. I would also like an easy way for the user to style and color each visual element.

Can this be done? What would you charge to perform this kind of customization?