What's possible with Outlook add-in development?

I am in the beginning phase of creating ideas for an Outlook add-in project, but being a newbie to add-in development, I seek advice as to what is possible with Outlook add-in development.

I plan to create a kind of "dashboard" for Outlook that would summarize, by calendar day, related email headers, appointments, tasks, contacts and notes.  In the https://docs.microsoft.com/en-us/office/dev/add-ins/outlook/outlook-add-ins-overview I found that "The Outlook items that support add-ins include email messages, meeting requests, responses and cancellations, and appointments."  Should I consider the aforementioned list to be exclusive of tasks, contacts and notes?