I have been using a program a lot like AlacrityPC that minimizes the background processes and shuts down Windows Update while the game is running. What I discovered is that Nvidia is now installing a Customer Experience telemetry system. Since it comes in with GeForce Experience you might expect that removing GE would also remove the telemetry, but that is not the case. I had to use the display driver uninstaller to remove the driver and then install using the custom routine. This is not good, because the custom routine has been known to be buggy and leave the drivers in an unstable condition under Windows 10. It seems to be alright for now. There is also a hotfix for game stutters (375.76), but it does absolutely nothing for AH3.
I still see the petite freeze issue, cloud shadows flickering, and hopefully the game minimizing is tied to the telemetry of GeForce Experience and I won't have to worry about that again. I didn't see any of it today, so far.