I was in a semi-similar spot. I have a 17 amp 220v air compressor that I wanted to auto-fill so it would not be empty when I need to use it, but not auto turn on during certain times of the day. My electricity plan has “peak hours” where the kWh rate is not only higher but they also charge you based on the highest amp draw you had durring those hours for the entire month.
After a good amount of searching, I could not find anything that was reliable for that kind of load on 220v system. So I ended up using a sonoff relay connected to a contactor.
The sonoff relay I got was for USA 110v system and is only 1 output so you can not do a straight copy of my setup. For your situation (if wifi is ok), I would look at perhaps using a couple 4 channel sonoff modules (that should be able to be ran off of 5v usb) and then connect them to your contractors.