I have a pair of Sony WH-1000XM3 headphones and use them literally every day, most of my waking hours. I'm really addicted to music and my day would be ruined without it. I use Bluetooth to connect them to my phone and the 3.5mm cable when using them on my laptop. A few weeks ago, I forgot the cable at home and had to use the phone all day, since there is no support for Bluetooth in OpenBSD.
This little device works out of the box and handles the Bluetooth part while presenting OpenBSD with an audio device over USB. However, you will need to configure sndiod(8) to send the audio to the rsnd/1 device, like this:
$ doas rcctl set sndiod flags -f rsnd/1 $ doas rcctl restart sndiod sndiod(ok) sndiod(ok) $
I'm not sure why, but you can't control the volume using the mixerctl(1) utility. Instead, you will have to install the aucatctl package.
$ doas pkg_add aucatctl $ aucatctl master=80
I've used this little beauty for the last couple of weeks now and I love it! I can finally enjoy wireless audio like everyone else, but without the security mess that comes with Bluetooth.