I will add my wish for subnotebooks. The fact is, different people think differently about how to organise things. My own personal preference would be to use a fixed structure in the form of a hierarchy of notebooks and then to add tags to allow searching and categorisation in a way that cuts across the notebook organisation. I use the same strategy in organising my photos in Lightroom, with a folder structure plus tags. Without this EN becomes less interesting for me and I anticipate using it now for relatively small collections of notes. So +1 to the suggestion.