And about needing to use higher end equipment, well it’s a evolving sim, if they add new capabilities, they will need further optimizations to free up resources or need more resources to run those improved effects. But as long as there minimum system requirements stays the same, they are not doing anything wrong by improving things that may need more capable hardware. Now if actual improvement is happening or not, well that’s debatable. I am sure they will optimize things when they can.
But I don’t see them using Vulcan, it’s backed by Microsoft, the creator of DX12 and Microsoft has very capable DX12 engineers who can help them out. They have no incentive to use Vulcan. Xplane uses Vulcan because it’s multiplatform (Linux/Mac) and Vulcan/OpenGL are the better alternatives in those cases.