Anyway, why not use Teams/Zoom and their "share screen" feature ?
My experience using Zoom was pretty bad. The pano motion is very jerky, for instance.
Anyway, for my purpose I want the user to have full control of the view when they want, just as if they were there in person. But I also want the presenter to have the ability to force the view or force a popup so everyone is looking at the same thing at the same time. I also want to force everyone to switch to the next pano at the same time, again, like on a real tour.
That sounds server-side to me.