I have an MX Keys that is connected to my iMac via bluetooth AND the unifying receiver. On the keyboard i have device 1 using bluetooth and device 2 using the receiver. I do this because sometimes the bluetooth has issues and the keyboard stops working. I can switch to the receiver when this happens. In the old app, the device is listed once but the connection method icon will change between bluetooth and receiver symbols depending on whether i've selected device 1 or device 2. In the new app, the device is actually shown twice. One is inactive and the other is active. If i switch between device 1 and device 2, the active device changes. I prefer the behavior in the old app where the device is shown once and the connection symbol changes based on whether it uses bluetooth or receiver. See screenshots in attached pdf.