Sorry to insist but in my opinion what is also missing in the Events Settings is the option to select a Custom Sidebar Choice if we select a page template like Two Column Left Navigation. Could it be possible?
The events already come with a custom sidebar widget area named “Events Sidebar” that you can use exclusively for populating the sidebar specific to events. Are you looking for something more than this? At present, it is not possible to set separate sidebar for each event. You will need to populate such an information as part of the event content itself instead of the sidebar. Hope this helps.