Control One Two DJs

Hey, I have a Denon MC 7000 and use both USB Ports to connect two Laptops, each with SS. Also I would connect both laptop to Control One.

Must I always use the usb-switch on Control One to set input laptop or is there a way that only the fader / crossfader on MC 7000 lets Control One know, which laptop is the source ?

Regards Ralf