It seems that the DirectGMA extension is formally supported only via "legacy" APIs - OpenGL, Direct3D11 and OpenCL.
Is there a plan to support this feature in more modern APIs?
Can the industry even rely on that feature being supported in the future?
As far as I know it is not included. If you provide additional info on the Vulkan based application and number of users we can check the feasibility and submit it as a feature request.