I don't believe there are any games that currently support DX12 Ultimate, but I could be wrong about that. There is one thing in the driver that could be relevant now. "Hardware-accelerated GPU scheduling". It can be enabled in Windows 10 2004 after installing this driver.
"This new feature can potentially improve performance and reduce latency by allowing the video card to directly manage its own memory."
I've enabled it. I'm not sure it's helping anything, but nothing has crashed yet.
I pwnz j00!