Something I would like to suggest that is kind of related/parallel to this: when the right panel is open, showing a date or a range of dates (I’ll just refer to a date, to keeps things simple, but it would also work the same for ranges of dates) and events, have another section below (similar to “Recently edited” and “Related” notes, probably above those) called something like “Linked notes”, listing all the notes, from all projects, that are assigned to the date that is currently selected. I can’t decide if this should also include notes linked to calendar events on that day, or just notes without explicit event links associated with the date as a whole – I would probably personally say yes, but it’s possible different folks would have a different preference for that.
I know it is possible to browse and search for notes from a particular date in the main panel, but it would be nice to be able to select dates on the calendar and see all the events AND notes from that date listed for you, updating simultaneously.