Hello.
The project is a 'one pager' with a 'start' page. For the 'one pager', no navigation is necessary (Survey.showNavigationButtons: none).
With that property set the 'Start' button is not shown on the 'start' page. Logical (it is a navigation 'device'), but to expose it, all navigation buttons are exposed. The Survey.showPrevButton is a partial answer but I think all navigation 'devices' should have a 'visibility' property.
Now, I will code a function to set Survey.showNavigationButtons from the 'onStarted' event to 'hack' this but kindly consider my suggestion.
Met vriendelijk groeten,
Max