Hi AbnerSun,
If you could re-build UEFI on your host PC.
Please try to modify the following content in edk2-nvidia/Platform/NVIDIA/NVIDIA.common.dsc.inc
to 0
gEfiMdePkgTokenSpaceGuid.PcdPlatformBootTimeOut|L"Timeout"|gEfiGlobalVariableGuid|0x0|5
You would decrease boot time of UEFI for 5s.