Play/Stop using earphone playback controls

[ropery]

I actually tested this with a Bluetooth speaker.
I tried to toggle between play & stop by pressing the button on the speaker, to no avail.
Presumably, it doesn't work with playback controls on earphone wires either.

I'd like to request this feature. For me, play/stop toggle would suffice. A further idea is to have previous / next track controls change the sound effect.