Currently you can insert time codes like 00:01:23 (HH:MM:SS) in Microsoft Stream video comments (see https://docs.microsoft.com/de-de/stream/portal-comments). I would like to mention people in the comment like "@HumanAtTheTableOppositeMe: Did you see at 00:02:34 the cool thing that we can do in our team too?". It should only be possible to name the users who have the right to watch the video. When modifying permissions, the mentions are preserved, but the link does not work.
Or that only works for global videos and not for group videos.
It would be very nice if the said user receives a notification that he was mentioned in a comment (of course, for each user switchable).