Do you run in windowed (macOS-native) fullscreen or (what I assume is) direct-to-graphics-card fullscreen? The windowed fullscreen performance was abysmal compared to when I switched to the other. I forget what the default was, but it's worth investigating.
On Windows it's probably more performant either way, but at least with the above change I was able to at least run it playably on my 2017.
