A notepad with its own hierarchy would be nice. Something like Jot+ from Kingstairs Software - https://kingstairs.com/jot/

I use it for notetaking, but it's cumbersome having a separate programme running

Hi, Matthew.

Thanks for the great suggestion. We’re doing some research about how to implement this, so that we can have different views of the same research at various levels–with cross-linking between the notes and the manuscript and also story elements like characters.