For people who are curious. I did more research. No, it isn't smoother on MCU3. The lagginess is due to software, not hardware being too slow to run it smoothly. On a good note, various aspects of the FSD visualizations got much smoother after the 2022 Christmas update on MCU2, further confirming that it's not a hardware problem. The camera movements and the lane movements are now 60fps smooth, but the movement of the cars and pedestrians are still laggy. This is most likely because the NN's are running at ~24fps, and therefore it can't be shown above that frame rate. That said, current frame rate for detected objects in the visualization is not 24fps, so there's definitely room for improvement there. Hoping V11.3 is going to make an improvement on that.
Also, AP3 cameras have a max frame rate of 36fps, and Elon has stated intention to run at the full 36fps, so that will be the max possible frame rate for detected objects for future software improvements.
