Yes, but I wouldn’t say this is very uncommon to do. For example, in the image below you can see the last hour meter reader in my house, you can see how my oil oven behaves when set to 750 W (note that Piggy is set to 10kW this month, so it doesn’t turn on/off anything in this interval, it’s all what the devices do themselves):
The oil-oven can be seen everywhere it’s a lot of switching. It’s on with 1500 W 30s, then off for 30s, with an average of 750 W… I don’t think the Aeotech switch will take damage using this kind of switching, but I would be more worried about doing this with AC devices.
In general, I think it’s better to use the temperature-control of piggy rather than the on/off switching. So if you have a temperature reading from the water heater, then I would rather create a virtual thermostat device for it and tell piggy to control the temperature. Then set temperature control to “preferred”, then piggy will never turn off your device, only change the temperature, then the virtual thermostat will translate this into on/off.
No, but I think you can sett the switching time in the virtual thermostat
