I am not a tech-guy, just a frustrated photographer. But I just to tell about something that almost fixed the issue for me, so it might be helpful for others. After seeking technical support from service and repair shops that I know well, and usually comes recommended, I found a solution.
I got a Wavlink dock, which used Displaylink Monitor. I guess it somehow separates the power drain and the signal, I don't know how it works, but the fans stopped running and the MBP did not slow down at all. But a new problem appeared, because it needed software to transmit the signal (no image displayed without it), the Mac had problems recognizing my Eizo, and for example Davinci could not engage dual monitor mode, and screen options could not recognize what display was connected. But that I could work around, but the biggest issue was that neither Colornavigator or Spyder could calibrate the Eizo, so for me as a photographer, is was unusable since the colors were way off for my use. But if you can live with oversaturated and off colors, for example for office use, that could be a solution.
I tried another 500 usd docking, that let me calibrate, but did not fix the fan/slow problem. I have now given up, bought a minimal used Mini M1 16gb 8/8 while I wait for the new M1X chip next year. I will complain to my Mac dealer on my MBP, and the consume rights in Norway is pretty good, so I expect a refund, even though it might take some time. For me they did not deliver what I was promised. It's like buying a car, and if you put someone in the passenger seat, the engine only gives you 50% power. It was said to operate extra screens, and it really don't.
