Jyri:
> Has anyone gotten a Bluetooth headset with microphone working yet?
...

I don't have any bluetooth headset, and I don't use it, just programming
some devices for it, so no, but:

There are two variants of Bluetoth, classic and low energy (BLE).
If your headset is using the classic one, you probably need bluetooth
legacy support.

First of all, you need to "see" the other side, try something like
(you need to stop bluetoothd first):
https://www.hackers-arise.com/post/2018/01/30/bluetooth-hacking-part-2-bluetooth-reconnaissance
https://wiki.archlinux.org/title/Bluetooth#Pairing

Regards,
/Karl Hammar