Enabling the MQTT to make Shelly 1 to work with HA will disable the Shelly Cloud support… and because of this, it will not work in Google Home anymore. 
Is there a way to have them both working like any other device? This is a big limitation to me, since I really like the integrated solution offered by Google and I use HA only for those things that I couldn’t do with it.
I reply to myself… I used the rest platform via HTTP… the only solution I found so far to control the Shelly without enabling MQTT.