Xcode 12: environment overrides setting in panel is not reflected on Simulator

Question

I follow a YouTube video on new stuff of iOS 14. Now we could set environment overrides via the panel. But I found the changes like Text Dynamic type is not reflected on iOS simulator. I search around, it is quite new, no related information I found. Is there anyone met the same issue here, how to fix it?

There is a warning "2020-07-18 11:46:25.479202+0800 SwiftUITest[32945:888273] libMobileGestalt MobileGestaltCache.c:38: No persisted cache on this platform." in the console. Not sure if it is related.

MacOS: 10.15.6 Beta (19G71a)

Xcode: 12.0 beta 2 (12A6163b)

import SwiftUI

struct ContentView: View {
    
    @State private var text = "Hello, world!"
    
    var body: some View {
        TextEditor(text: $text)
            .padding()
            .foregroundColor(.blue)
            .font(.custom("Georgia", size: 24, relativeTo: .largeTitle))
    }
}

struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        ContentView()
    }
}