Currently this component reports guest devices into the known_devices.yaml file. That is users connecting through our guest network through a guest portal. These devices are registered even though they are not properly authenticated as Unify registers these in the database on first connect.
Regardless, I want an option to turn Guest detection off as it builds up a quite large known_devices from all devices automatically connecting to new networks when walking by… 
I had similar problem and started using nmap_tracker.
I gave all my devices I want to track a fixed IP-lease in my router and just track the IP-range I want to track.
In this way I have full control on the IP’s my devices have, the devices I track in Hassio and all guest devices are ignored or you can track them in a different way.
I do this to see if new unknown devices enter my home so I can check what devices it are and take action : refuse them or allow them and give them a fixed lease