The cache relies on the vulkan driver's shader cache to do the actual caching and uses VK_EXT_shader_module_identifier to skip compilation if a pipeline is present in the cache. There is no point sharing it, if that's what you're asking.
Thank you for the answer.
FWIW the DXVK state cache isn't fully hardware agnostic either.
Nothing extracted yet.
Or is it hardware agnostic like dxvk state cache?