Using `cast_site` to cast a HA dashboard to a Nest Hub. Command to change the view on the hub?

[trireme32]

One thing I'm trying to implement is having the dashboard screen change to the /nowplaying view I've set up, when music starts playing on a device. I've set up a shell command with catt -d "device name" cast_site http://*url*/*dashboard*/nowplaying, but while that does not return an error it does not change the view on the Nest hub. Nor does running catt -d "device name" stop first.

Any other suggestions?