When you want to try it – remember, I’m working and running X-plane on macOS Catalina – I suggest that you install a separate version of X-plane on your desktop or if not too big, make a copy of your current X-Plane and name it in such a way that you know that this is 11.50b1.
Anyway, I did a quick test on my iMac Pro and I was positively surprised. My default X-Plane configuration which is just a basic X-Plane ran in a certain condition 65 FPS but with “Metal” selected, and after a restart, I had under the same conditions 97-99 FPS. Again, it’s just a basic X-Plane configuration with no add on aircraft or airports installed. Yes, you would say .. that’s not fair. We don’t fly with a basic clean X-Plane configuration. Right, I don’t do that either, but for comparison reasons it is a quick and easy way to see what happens when you tick or activate Metal in the Rendering Settings – Graphics.
Do you want to give it a try? It’s worth it although you need to keep in mind that it’s b (beta)1, and please test it with a separate X-Plane package, not your regular package. Questions, thoughts, own experience, just ask or let us know!