I actually tested DX12 a few weeks back (you just add to the project as a gfx choice), but it caused a crash when the occlusion manager was on. Unity replicated and thinks it was nVidia's drivers, so I retested yesterday with the latest drivers and did not crash, but I do get a DX12 error (x2) on world exit, which I told Unity about. We do want to support it, but FPS seems the same. I still have DX12 enabled in the Unity editor, which also has that error (x2), but they don't seem to break anything other than making the console open.