Is it possible to package a game with DX12 exclusively?

Hello guys. I have made a demo to test the performance of dx12 in UE4 and I would like to package (ship) this demo for testing on other PCs. I’ve tried several ways yet failed.

  1. Launch UE4 in DX12 mode with -DX12 and package
    When I started UE4 in DX12 mode I could tell from the log that the RHI was assigned as DX12:
    LogD3D12RHI: Chosen D3D12 Adapter Id = 0; LogD3D12RHI: Emitting draw events for PIX profiling; LogD3D12RHI: The system supports ID3D12Device1; LogD3D12RHI: The system supports ID3D12Device2.

    However after shipping, the packaged demo still runs in DX11.

  2. Launch UE4 in DX12 mode & In Project Settings - Platforms - Windows untick DX11 and DX10 (no DX12 appeared in this section)
    Still, aftering shipping, the packaged demo runs in DX11.

Many thanks!