Honestly, I think this is because the fan is targeting more than just the CPU temp. When charging, the power conversion circuitry can get fairly toasty as it wolfs down a full 60 watts. That may be the cause there… maybe.
I dug into using NBFC for battery control and gave up after stumbling into a big roadblock: it only takes one arbitrary value, “register”, as an 8-bit value (0-255) and have single byte (or word, as an option) outputs. The values for EC are 16-bit addresses with variable length values, so it doesn’t make much sense, didn’t know how to convert it. Maybe NBFC is made for an earlier generation of laptops, prior to this whole Windows 11/“always connected”/new-world-ROM sort of thing. I suspect an entirely new generation of EC goes along with it.
All I really want is user-land battery control, but since I power my laptop solely by battery bank (OmniCharge 20+) and solar juice, I’m almost always running on battery anyway, and the battery inherently stays in its happy zone (anywhere under 90%) just by usage patterns. Been an EV nerd for over 10 years now, so the car and the laptop batteries both ought to last basically forever. haha