Question about Epson EF-12

Yes, it has a Bluetooth function with which you can pair your audio player (e.g. smartphone) and play music via the projector speakers.
The remote control also works via Bluetooth. This has already led to an error when I used the above-mentioned function. After a restart, everything was fine again.
(I don't know if you can also pair other speakers to the beamer via Bluetooth in order to forward the beamer audio. In principle it should be possible, as the beamer runs Android, but it is not enabled. I haven't managed it yet).

No, unfortunately the beamer does not have a Bluetooth function.