Hi Dave,
actually have one of those, they included it in my p121/sx900 package.
To be quite honest , I haven’t really played around with it too much.
I tried it with the p121 and the piano app, when I first bought it, but I must have been doing something wrong, I couldn’t get them to connect. I eventually got the camera adapter , to work , so didn’t want to start messing around with it.

Never really used Bluetooth for anything except for the phone connection to hubby’s car.
That was a nightmare too, had to take it back to BMW, to get his $12 flip phone ( which did actually have Bluetooth) connected to his $80k BMW. Should have have seen the lady technicians face, priceless, when she asked him why he didn’t get a decent phone. His answer was, oh, I could have spent $18 for the upmarket version, but I did want to spend the extra. Haha.

Thank goodness the kids bought him an iPhone for his 70th birthday, he wouldn’t let me do it.

Couldn’t get that open mics link to work, so looked it up on google.
Interesting.