How to Include Optional Attendees in Calendar File when Converting It to MHT

Save a calendar ICS or Msg to MHT using MhtFormatOptions.WriteHeader | MhtFormatOptions.RenderCalendarEvent produces something like the following example:
The output doesnt show Optional attendees. Could some one help me with displaying Optional attendees along with the following information in MHTML file genereated using RenderCalendarEvent

Subject: Test Appointment
Location: [https://consilio.zoom.us/j/test ](https://consilio.zoom.us/j/test)
Start: Fri 10/01/2021 08:30 PM
End: Fri 10/01/2021 09:00 PM
Show Time As: Busy
Organizer: John
Required Attendees: Mary

@pkometineni,
Thank you for contacting support. We will answer you as soon as possible.

@pkometineni,

We have reproduced the issue and started working on a fix. The EMAILNET-40440 task is registered in the Email project tracker. We will notify you as soon as the issue is resolved.

@pkometineni,
Starting with upcoming version 21.10, optional attendees will be displayed in output MHTML for MhtFormatOptions.WriteHeader | MhtFormatOptions.RenderCalendarEvent options.

Also, you will be able to disable them in the following way:

// MhtSaveOptions 
options.FormatTemplates[MhtTemplateName.OptionalAttendees] = "";

The issues you have found earlier (filed as EMAILNET-40440) have been fixed in this update.