With regard to of DX12 mode in version 4.22, in the latest version of , at least putting into the scene and picking up the sky sequence won’t collapse immediately, but it’s still unavailable.
In 4.1a, after step, the sky became completely black, no sky appeared, and the adjustment of parameters in the sky sequence was invalid.
In 4.2, sequencers and sequences can be added normally, but most scenarios will crash in a few seconds, mainly in graphics driver, so is still not available.
I used WIN 10 1809. RTX 2080 TI graphics card, the latest NVIDIA Sdudio driver, Unreal 4.22.2 for testing.