Knowing if this is going to be implemented would help me to decide deploy this app in my office, or search for alternative.
When the account name is different from the user name for authentication, ask the user, whether the email for authenticarion shall be inserted as ORGANIZER;SENT-BY=…
When the CN after ORGANIZER or ATTENDEE is the same as the mailto: address, do not insert CN. This has no added valie and just increases the traffic.
Obtain from the user its name and use it as CN for the ORGANIZER, or get the name from the principal-url (if not already done), perhaps as its displayname. The CN is used layer by rhe server ro send emails and it appears as display-name. So with proper CN the email will lool nicer.