A general observation:
The “pattern establishment” possibility of any relatively low wattage device is going to be lower than a higher wattage device with the same signature physics and usage patterns. Another way of viewing that is “the lower the wattage the higher the noise” (in the on/off detection and the usage pattern).
As one would then expect, Sense is good at large kW water heaters because the ons and offs are more likely to be distinct. Rough analysis on my system, using dedicated Sense CTs on my HW tank circuit vs Sense-native detection on two Senses, is that it’s around 94% accurate, by some measure, on my fairly simple electrical network. That’s an interesting number because “95%” is a typical confidence that you might work with before “moving on”.