I’m not sure if others would find this useful, but I find it limiting to have to expand and scroll through the contents of long lists of folder contents in the left-side menu. Especially because there is no way to view the items there in any way other than as a long list of basic file names.
So I think it would be nice for folders to have an actual “view” when clicked on that showed their contents on the right side. It would be the same as the first level of their contents, just like a file manager, showing different things with different icons, just as in the left-side menu. What would make this more useful though is to be able to switch to different views, again just like a file manager. Thumbnail view to see quick previews of Doc or Whiteboard contents, for example, or even “Details” view if you have the ability to store e.g. creation and modify date for Docs and Whiteboards (even if they are not an “Entity”/Type and you cannot add more fields). And just in general to have a more visual way to browse through and distinguish things would be nice.
It would enable new capabilities as well, like multi-select files (“views” I guess), e.g. docs and whiteboards, and move them all collectively inside a folder. Again the file manager example is very apt, and I think it could be useful here for the same reasons.