No. Firstly you don't have to connect them to Alexa or Google. They run on an app called Ewe-link, which you can connect to Google or Amazon if you wish. If you don't want to use that app you can run them locally, using open source projects like Home Assistant or OpenHAB. At the moment I am running them through Google Assistant because Google's timing routines are very reliable. I am working on using OpenHAB so I can take them off grid, but that takes time as I have dozens of smart devices all over the house.
You can name them whatever you like, so I have created a room called Conservatory, you could call it anything you like such as Garden Shed or Spare Room. As I hardly use my Conservatory I figured that would be good. In my conservatory I have a Heater (Flower tent) and a Dehumidifier (Veg Tent). I don't control them via voice on Google, because there is no point. I have just setup a routine that turns the heater off at 5am and on again at 5pm. The accuracy is superb, they haven't gone wrong once since April and they auto adjust when the clocks change. I have also taken the precaution of having a guest network so any guests don't have access to my smart devices which reside on my personal network. They are perfectly safe IMHO.
Sonoff stuff is top quality. I am going to invest in one of their Zigbee hubs. Zigbee allows you to connect various sensors to you smart home. They do a temp/humidity sensor. It is my plan to install one in each of my tents and when the temp or humidity reaches certain thresholds it will be able to turn on or off heaters, fans, exhaust fans and so on. But again you don't have to use Google, Amazon or their app, it is your choice how it works. Obviously, the more off grid you want to make it the more technical skills you require.
Ewe-link also do an app called Ewe-link Camera. You can install it on an old phone for free and it will use the camera as a small CCTV camera, so you can connect to it over Wifi and see what is going on in your grow room.