It's probably a web 3.0/IoT way of saying an ESP8266 with a couple of sensors and a relay. From there you could do some slightly smart stuff like observe the rate of warming towards ambient when idle (i.e. determine the volume of material in the freezer) to determine how long you can go without running the compressor. And from there you could manipulate the thermostat's target depending on current and future predicted electricity prices.
With a load sensor attached to the tub, you could determine when a substantial volume of new material has been added and preemptively run the compressor hard for a bit.
Many things are possible. Most of them not worth the complexity.
Well, theoretically you could just use 3-phase motors, right? I'd actually like that, and over here in Germany, most homes have a 3-phase supply in the kitchen for an electric stovetop.
More efficient than single-phase. In this case, it makes the inverter redundant, because the inverter's only purpose is to produce a 3-phase AC supply for the motor.
With a load sensor attached to the tub, you could determine when a substantial volume of new material has been added and preemptively run the compressor hard for a bit.
Many things are possible. Most of them not worth the complexity.