Every time i search for this topic, i only see couple discussions from years ago and another post on reddit recommending to set the processor scheduling to “background services” in the computer performance options, hence the sim uses a lot of services while running ala weather, photogrammetry etc…
it is set usually on programs because you want that programs get more cpu time, instead of the background services. And also MSFS is such a “program”, whatever it internally do, and not a background service…