I think this is more of a documentation / audit / impact analysis requirement than a normal in-app feature.
If your goal is to generate a list of all input fields used across pages, then you are basically trying to read the app model metadata, not runtime data. For that kind of requirement, doing it inside the app through a nanoflow or JavaScript action may not be the right approach.
A better option would be to use the Model SDK externally to scan the pages and export the details into CSV.
So I would first clarify:
That clarification will decide the correct solution.