There is a class of extensions that were only created to allow efficient ways for translation layers to map to Vulkan.
This includes replicating legacy behavior that is challenging for drivers to implement efficiently. This functionality is not considered forward looking, and is not expected to be promoted to a KHR extension or to core Vulkan.
Unless this is needed for translation, it is highly recommended that developers use alternative techniques of using the GPU to achieve the same functionality.
The depth clip enable functionality is specified differently from D3D11 and Vulkan. Instead of VkPipelineRasterizationStateCreateInfo::depthClampEnable, D3D11 has DepthClipEnable (D3D12_RASTERIZER_DESC), which only affects the viewport clip of depth values before rasterization and does not affect the depth clamp that always occurs in the output merger stage of the D3D11 graphics pipeline.
Vulkan's defaults convention for provoking vertex is "first vertex" while OpenGL’s defaults convention is "last vertex".
Everything needed for transform feedback can be done via a compute shader in Vulkan. There is also a great blog by Jason Ekstrand on why transform feedback is terrible and should be avoided.