The big question I have is whether this can possibly support mandatory Vulkan features that are not available in Metal. The one I care about most is device scoped barriers, which in turn are needed for single-pass prefix sum techniques.
The specific thing I asked for is very technically challenging. One of the things I can offer is some tests that fail in, among other things, MoltenVk, as the mapping to Metal barriers is imprecise. I'm not sure whether the Vulkan CTS test will catch it, I've seen it miss memory model failures on other hardware. I'm always happy to chat about this if someone from the team wants to reach out.
Alyssa and Lina are very responsive on IRC. #asahi-gpu on OFTC IRC network. You best ask them. Whether metal or moltenVk supports it doesn't matter. The hardware is capable of more.
