No nothing close to that number. At the most 1000 but usually in the hundreds.

If you mean setting the preferredConfiguration on MKMapView to MKStandardMapConfiguration(elevationStyle: .flat, emphasisStyle: .muted) that does not work for me.

Yeah, that does help. But as you say if you need to style them individually you're out of luck

I feel your pain. Have done some hacky workarounds to make it decent. One thing that also seems to affect it is if overlays are removed and re-added to the map. Never removing overlays seems to help but it does not mitigate it completely