Lag is unimportant for the application OP is after (car reference test). But this is not Cubase issue. Cubase will happily send audio to Bluetooth audio device if it has ASIO interface. This issue is discussed in previous topic:
Lag is unimportant for the application OP is after (car reference test). But this is not Cubase issue. Cubase will happily send audio to Bluetooth audio device if it has ASIO interface. This issue is discussed in previous topic: