Ah, I think the missing icon is just that, the Entegra do support Metal/Vulkan. The FPS of the Entegra vs G1000 will depend on your CPU/GPU combo. The CPU on the Entegra is very multi-threaded, so if you've got many threads on your CPU it will scale well and do well. If your CPU doesn't have many threads, there could be the opposite effect.
Both the G1000 and Entegra should work great in VR. The Entegra itself is a bit easier to operate as the screens are less cluttered, but that's just my preference.