According to Technet it should be possible to add a Factbox component to role center pages. But I don't have the option to add this when clicking "Add new web part".
I can find plenty of resources on how to customize or modify existing factboxes. But I can't find any guidance on how to add a new one to an existing page.
As I remember, you can add FactBox only with ListPage form to EP page. Please, take a look at this white-paper https://msdn.microsoft.com/en-us/library/gg886593.aspx