I haven't tried this but it could work.
Assuming there is a background that could be the non-linked area, you could make the background a link to a duplicate of the page, but on the duplicate the clickable areas are highlighted in some way, i.e. a solid colour over all interactive elements, clicking anywhere on this page could then take you back to the first page
when you say preview mode, do you mean the preview in the app or in the browser?
We are currently working on a feature that would you allow this in the browser and it should be available to you very soon.
Please let me know if this would solve your issue.
Just wanted to circle back and let you know that this feature just landed this week! On the shared prototype, you should be able to tap on any spot and see a highlight.