Automatically scales the font size in respect to dynamic type size changes.

SwiftUI+ScaledFont.swift

public extension View {
    func font<T: BinaryFloatingPoint>(_ scaled: Scaled<T>) -> some View {
        modifier(ScaledFontModifier(metric: scaled.value))
    }
}

public struct Scaled<T: BinaryFloatingPoint> {
    fileprivate let value: T
    public static func scaled(size: T) -> Self {
        .init(value: size)
    }
}

private struct ScaledFontModifier<T: BinaryFloatingPoint>: ViewModifier {
    @ScaledMetric fileprivate var metric: T
    func body(content: Content) -> some View {
        content.font(.system(size: .init(metric)))
    }
}

Example:

#Preview {
    VStack {
        ForEach(DynamicTypeSize.allCases, id: \.hashValue) { size in
            Text("Auto Scaled")
                .font(.scaled(size: 14))
                .dynamicTypeSize(size)
        }
    }
}