I get the same sensation.
Did 2nd wash today, monitored on ZEN15. Maybe 9 lb per b-room scale.
No evidence at all of heating element coming on.
Perhaps indeed it is only to boost hot water temp to the "extra hot" manual, and not like the guy in that video hinted, although it is summer here, warm temps good for heat pumping.
I bought that extended warranty because of video guy too. Hope he's wrong about that too. 
I don't think I'm gonna graph it. It approached 800 watts at one point, and high 700's at others, but for very brief periods.
kWh usage per ZEN15: 1.192
kWh usage per LH ThinQ app: 1.07
edit: The load indeed was smaller than the first, with ThinQ said took 1.42 kWh.
