BlueSound does not support Chromecast, hence users can't cast from the JUKE app to a BlueSound device. 

On the BlueSound website it is stated that the current Bluesound Player lineup does not include microphones, hence supporting Chromecast is simply not possible. 

For more information, see Bluesound website: https://support1.bluesound.com/hc/en-us/community/posts/4412978980119-Where-is-chromecast-