Thanks for the quick and comprehensive answer. I may add as usual 
I don't understand what:
- url
- usews
are.
If the broker String starts with ws or wss it declares it as a websocket broker. So, what is the benefit of using usews: true
Another question, do I need usetls: true (or box ticked) for the client to use MQTTS or WSS to connect to the broker? If the broker config starts with wss:// is it implicit that it has to use TLS?
Finally, for the tls config, one option could be to declare fix names in the configuration and push the "right" cert, key and ca in another flow...
I just need to check if usetls is true, I have "fix" files for the ca/cert/key and they are not present if everything works anyhow.
And for url, I can't see that in the config...
