SwiftUI: Remove 'Focus Ring' Highlight Border from macOS TextField

I used the below code to create a custom search bar in SwiftUI. It works great on iOS / Catalyst:

...but when running natively on macOS, the 'focus ring' highlighted border styling (when the user selects the text field) rather ruins the effect:

Using .textFieldStyle(PlainTextFieldStyle()) has removed most of the default styling from the underlying field (which I believe is an NSTextField), but not the focus ring.

Is there a way to remove this too? I tried creating a custom TextFieldStyle and applying that, but couldn't find any modifier to style that border.

public struct SearchTextView: View {
    
    @Binding var searchText: String

    #if !os(macOS)
    private let backgroundColor = Color(UIColor.secondarySystemBackground)
    #else
    private let backgroundColor = Color(NSColor.controlBackgroundColor)
    #endif
    
    public var body: some View {
        
        HStack {
            
            Spacer()
            
            #if !os(macOS)
            Image(systemName: "magnifyingglass")
            #else
            Image("icons.general.magnifyingGlass")
            #endif
            
            TextField("Search", text: self.$searchText)
                .textFieldStyle(PlainTextFieldStyle())
                .foregroundColor(.primary)
                .padding(8)
        
            Spacer()
        }
        .foregroundColor(.secondary)
        .background(backgroundColor)
        .cornerRadius(12)
        .padding()
    }
    
    public init(searchText: Binding<String>) {
        self._searchText = searchText
    }
}

As of iOS 17 / macOS 14, you can use .focusEffectDisabled. You can also apply it to buttons or the entire view.

TextField("Search", text: self.$searchText)
.focusEffectDisabled()