We have also been testing the use of the Teams Plugin alongside the notification update that is sent out if room details (not just date and time) changes are made,  this allows us to add a link later if not available when the event/session is first launched.  Prior to this we were sending out separate calendar appointments containing the links for the very reason that they needed to come from the account of the meeting organiser, in order for them to be able to have the organiser functionality availalbe to them in the meeting.  Breakout rooms beign one of the key issues. 

We worked around the issue by getting our internal event facilitators to grant calendar permissions to our course administrator who could then instigate Teams meetings in their name giving them organiser status.  This isn't possible with the plugin (I don't think) as you need to login to teams with your account details.  There is however an MS365 Roadmap item (now scheduled for March '22) that will allow other attendees to be assigned co-organiser capabilities for meetings which will make the use of the plugin more viable as an option for these use-cases.

We have just moved to V14 and are generally looking to improve our workflows around Seminar activities and booking in general.