Trying to emulate a form where your second choice is divided into 3 possible sub steps, but they all come back together to the same summary page before submission. The pages themselves are stored in a flat hierarchy. Screenshots and sample data attached.

The sub steps before the summary page show the other sub steps as well even though they will not be reached and are set to "hidden in the navigation". However, the summary page then shows the correct state of the substeps. This leads to an inconsistent state of the "breadcrumb". Related to this, if you go back and make a different choice, it will be displayed in the final summary page as sub step as well (already reported in MGNLFORM-255)

Unfortunately it is also not possible to circumvent this by hiding this information without having to provide an own template script for that component/area.