@MerakiDave @BrechtSchamp
I have my Chromecast capable devices on their own VLAN.
A smartphone, needs to be on the same VLAN to control the Chromecast device. However, once the device has started casting, the phone can detach from the VLAN.
At some stage I shall experiment with Bluetooth, although, at present, the IoT WiFi is not Bluetooth aware, but technically the Chromecast devices can use Bluetooth. There are security reasons for being very careful with Bluetooth.
In this environment, the video devices, including Smart TVs, do not stream videos as directed by another device(phone), but rather connect to the internet source directly, at the margin, this allows greater throughput and smoother playback.
Devices which need to access screens, STBs, playout systems etc, use HDMI to connect, not Ethernet.