I'm guessing here, so someone who knows confirm. The IP addresses of the controller and solo are fixed. They're assigned 10.1.1.1 for the controller and 10.1.1.10 for the Solo. Other devices such as phones, tablets, etc are issued DHCP addresses by the controller 10.1.1.100-255. As such, you couldn't bind two controllers to one solo and expect two people to be able to control it. The two controllers would create an IP address conflict.