I don't know, I'll look into it. I assume pipewire-pulse is in use because it works with all the pulse tooling.
My macbook can't even figure out that it should try to connect to my offce trackpad after I have had it connected to my home trackpad! Thankfully it has a built in trackpad that I can use to manually connect when the "automation" fails..
I had a 12" MacBook no-adjectives in the past which didn't even work with AirPods well. I was hoping the M1 would have a better BT stack (the iPhone's...)