Yes, I haven’t tried the JEP package yet, because it looked like most of our JNI-based native libraries will continue to work (for now?). Re-writing our implementations of Jogl and VTK will probably be required anyway for Mac, so it will be interesting if that “incubated” JEP project gets better support in the meantime. Seeing your examples will definitely help when we decide to move over our implementations.
Switching to Metal or Vulkan (with JEP or some other Java native access) would be probably more work in the long run, considering how much we’d have to pay attention to details that would otherwise be abstracted (hence why we have used VTK in the past).