Can a guest take control of my smart hub using the code on bottom?

Thank you for your question. No, a guest can't take control of your smart hub through the code on the bottom. Once your hub is registered, it belongs to you and is locked in on your account. No one else can register that hub to control while it is on your Iris account. However, if you do want a guest to use it, you'll have to register the guest through your app to give them control, as the hub ID will not give the guest control.