Smart Home ZigBee to Google Home - Sonoff, Shelly, roller shutter and heating control

Hi!
I'm getting ready to do a major renovation of my flat and would like to use some Smart Home devices in it. In my current flat I use devices controlled via Google Home (I want the rest of the household to know how to use these devices). I currently have mainly Shelly (1 and 2 channel switches) installed for lighting, a 2 channel switch for controlling blinds. I also have 4 pieces of Sonoff Basic R2 to control standing lamps. The combination boiler is controlled by a Salus wireless controller. This all stays in the old flat.
I am therefore looking for devices, preferably over ZigBee, as there may eventually be about 23 devices and I would not like to clog up the Wi-Fi network. I mainly use Shelly, but I am considering Sonoff devices (also because of the price). And so I have adjusted according to my needs:
- 1-channel is a Sonoff ZBMINIR2
- the roller shutter controller is a Sonoff MINI-RBS
- the 2-channel controller is a Sonoff DUAL R3 (is there any other model with ZigBee?)
- temperature and humidity sensor Sonoff SNZB-02D
- sonoff SNZB-05P flood sensor
The target is to have underfloor heating in the flat - 7 or 8 heating zones - for this I have no idea yet whether there must definitely be separate management of all zones or not.

Please give me some hints as to how the Sonoff works out for you, or possibly something else, but to be well working and secure, and also to work with Google Home.

Quote:

Target is to have 7 or 8 underfloor heating zones in the flat - for this I still have no idea whether or not it must have separate management of all zones.

If you are to have zones separated by building partitions (walls, doors) it is useful to control the temperature for each separately.
I, in my third house, have additionally used the possibility of selecting circuits in large rooms that have several zones in each floor.
This can be done with a ZIGBEE multi-channel controller or several, but I did it electrically, in the distributor such a selector half on the switches.
However, it won't hurt to run cables from the thermostats to the manifolds( with a relay output, but supporting WIFI) to the manifold, preferably a minimum of 3 wires 230V.Dealing with WIFI don't worry about the controller using a few dozen MB in a week.
Greetings. J.