A UIFont extension to enable dynamic for system font styles with any font weight

SystemFont.swift

import Foundation
import UIKit

public extension UIFont {
    static func preferredFont(forTextStyle style: UIFont.TextStyle, weight: UIFont.Weight) -> UIFont {
        let font = style.withWeight(weight)
        let fontMetrics = UIFontMetrics(forTextStyle: style)
        return fontMetrics.scaledFont(for: font)
    }
}

public extension UIFont.TextStyle {
    var baseFont: UIFont {
        return UIFont.systemFont(ofSize: defaultPointSize, weight: defaultWeight)
    }

    func withWeight(_ weight: UIFont.Weight) -> UIFont {
        return UIFont.systemFont(ofSize: defaultPointSize, weight: weight)
    }

    var defaultWeight: UIFont.Weight {
        switch self {
        case .headline:
            return .semibold
        default:
            return .regular
        }
    }

    var defaultPointSize: CGFloat {
        switch self {
        case .largeTitle:
            return 34
        case .title1:
            return 28
        case .title2:
            return 22
        case .title3:
            return 20
        case .headline:
            return 17
        case .body:
            return 17
        case .callout:
            return 16
        case .subheadline:
            return 15
        case .footnote:
            return 13
        case .caption1:
            return 12
        case .caption2:
            return 11
        default:
            return 17
        }
    }
}