I’d love it if it were possible to save not only the current layout but also the documents that are open in that layout. I often have certain sets of documents I want to have open at once, and if I could easily switch between these sets of documents without having to open each one every time, it would be nice. (I know that the saved layout feature is not linked to specific documents, so I’m not sure how this would be implemented)
You could group the documents you care about in a Collection. It wouldn’t be tied to a specific Layout, but you’d be able to find them without rooting around in the Binder.
For individual documents and items that are already grouped in folders, you might also have a look at the Bookmarks feature.