Bluetooth.

There's some suggestion in the FAQs that the C-A has got some Bluetooth hardware. Can anyone who's got one see any evidence of this?

https://support.google.com/chromecast/answer/6260600?hl=en-GB&ref_topic=6279364&vid=1-635796243643786815-1838887243

Setup, iOS section:-
Highly recommended: Turn on Bluetooth to help improve the set up process.