Well technically it can handle infinite. How it works is as followed: every person in the world needs to know the actions of all people in a "world" and broadcast to every headset. It would be too much overhead starting from 80 people. How it works is that if more than 80 people attend HiveFest (and I expect so), it will be become a so-called "antenna" event which means that a second version of the same world is "spawned" and all contents of the stage (speakers, presentation) is spawned into all copies of the world. Leaving the world and re-entering will then mean that you could end up in a different copy with other attendees. This will be OK tho as you can reconnect with anyone through the message interface and then hop into a more quiet break out room for example. This is a thing which will be explained in future communications.