Well… we discovered that the api/mqtt.enabled field is messy. What you actually need to do is
curl -i http://<bridge>/v2/api/mqtt -H "BOND-Token: <token>" -X PATCH -d '{"enable": false}'
And you will see:
{
...
"enabled": true
}
Then reboot. It will still say enabled: true
but this is actually disabled. We are fixing the polarity of the field and the typo for next beta. But this should get you going.