Stealing your diagrammatic approach, here's my setup:
And here's what it looks like connected:
Add in the car's Bluetooth, Alexa, the Bluetooth-enabled microwave, work iPhone in the top box, and passing traffic and it's no surprise that nothing ever quite works as expected!
So after ten minutes wobbling down the road trying to press the right button on the headset at the same time as fiddling around with the thumbwheel trying to find the audio settings without turning off the spotlights, adjusting the suspension, buying something off Ebay and sending my bank details to the son of the former Minister for Oil in Lagos, I turn the bloody thing off and ride in silence, fuming at the expense of all the kit!