There is one pretty epic stackoverflow post that AI searches probably won't find.
It turned out a lot of the thermal throttling (kernel_task usage) on the i9 macbook pros went away if you plugged in the power on the right side, instead of the left.
Why turned out to be a chip (thunderbolt I think) that didn't have enough cooling.
https://apple.stackexchange.com/questions/363337/how-to-find...
One could also put quiet cabinet fans under the i9 Macbook Pro to make it draw air away and run markedly faster. [1]
That, combined with the keyboard failures, meant I could put a wireless keyboard on top of the laptop keyboard and use it, with fans underneath.
This is how I took it to the Apple store for warranty repair, which made a point of it having a pretty massive design flaw.
I asked them this if it was a feature of all macbooks when you buy the fastest ones to have to cool it the right way and not use the keyboard in case there might be dust in the air. The laptop was way too overspecced.
The i9 laptops were made far too thin to cool themselves appropriately in any situation, full stop.
All to say, if I could detect which USB-C port was pulling power in, on those laptops, I could guess pretty accurately what will happen on that i9.
It's sad to know the M4 Max Macbook Pro has the same issue, even though the laptop is thicker. Doesn't make me want to upgrade anymore.
[1] https://www.amazon.com/AC-Infinity-MULTIFAN-Receiver-Playsta...