Webinars (Live Video) is a great feature. However, to have external speakers as co-hosts, you have to onboard those users as site user with a role having a specific permission level: “Manage Events”.
That one is too broad as it allows the external speaker, to add, edit and view all events and mess with them.
Are you planning to better accomodate external co-hosts within Wix Event Live Videos (webinars)?
My suggestion is to add a more granular permission level allowing only viewing and joining a Live video. See here: