Hi David,
You’re right that you can duplicate forms if you wish, but you correctly mention that it would make changing your menu difficult. @p.colbert has spotted one possible solution, and the one I use myself, which is to have precisely one “home” form, with navigation menu. You can then add “sub” forms to the main form as content via code. For example, in the code behind your main form:
def nav_link_click(self, **event_args):
# This method is called when the link is clicked
self.content_panel.clear()
self.content_panel.add_component(MySubForm())
(Of course this will require a container such as a ColumnPanel on your main form called content_panel).
I hope that makes sense. Please do follow up and let us know how you get on.