The Mac efforts rely on MoltenVK for and Vulkan needs which itself relies on the underlying Metal API. As I understand it Asahi/Honeykrisp driver for Vulkan does not rely on the Metal API so it actually can do more conformant Vulkan than Crossover/Whisky can. For example tranform feedback and other geometry shader stuff will work on Asahi. MoltenVK is working on it, but not there yet.