Hi there,
I have a radeon and experience flickering shadows/artifacts on the ground. The Flickering seems to start below 250m. Above that height the picture looks good.
Current System is a Radeon RX470 4GB + Ryzen 5 1500X + 16GB DDR4-2400. But overall performance seems to be better than before the update.
Quick Edit: Radeon Driver is the newest one 20.4.2