UILabel and UITextView truncation issues

// a replacement for UILabel
class TextViewLabel: UITextView {

    public var numberOfLines: Int = 0 {
        didSet {
            textContainer.maximumNumberOfLines = numberOfLines
        }
    }
    public var lineBreakMode: NSLineBreakMode = .byTruncatingTail {
        didSet {
            textContainer.lineBreakMode = lineBreakMode
        }
    }

    override init(frame: CGRect, textContainer: NSTextContainer?) {
        super.init(frame: frame, textContainer: textContainer)
        commonInit()
    }

    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        commonInit()
    }

    private func commonInit() -> Void {
        isScrollEnabled = false
        isEditable = false
        isSelectable = false
        textContainerInset = UIEdgeInsets.zero
        textContainer.lineFragmentPadding = 0
    }

}

class ViewController: UIViewController {

    let labelStackView = UIStackView()
    let textViewStackView = UIStackView()

    override func viewDidLoad() {
        super.viewDidLoad()

        let scrollView = UIScrollView()

        let hStack = UIStackView()
        hStack.axis = .horizontal
        hStack.spacing = 8
        hStack.distribution = .fillEqually
        hStack.alignment = .top

        [labelStackView, textViewStackView].forEach { v in
            v.axis = .vertical
            v.spacing = 4
            hStack.addArrangedSubview(v)
        }

        hStack.translatesAutoresizingMaskIntoConstraints = false
        scrollView.addSubview(hStack)

        scrollView.translatesAutoresizingMaskIntoConstraints = false
        view.addSubview(scrollView)

        let g = view.safeAreaLayoutGuide
        let cg = scrollView.contentLayoutGuide
        let fg = scrollView.frameLayoutGuide

        NSLayoutConstraint.activate([

            scrollView.topAnchor.constraint(equalTo: g.topAnchor, constant: 20.0),
            scrollView.leadingAnchor.constraint(equalTo: g.leadingAnchor, constant: 20.0),
            scrollView.trailingAnchor.constraint(equalTo: g.trailingAnchor, constant: -20.0),
            scrollView.bottomAnchor.constraint(equalTo: g.bottomAnchor, constant: -20.0),

            hStack.topAnchor.constraint(equalTo: cg.topAnchor, constant: 8.0),
            hStack.leadingAnchor.constraint(equalTo: cg.leadingAnchor, constant: 8.0),
            hStack.trailingAnchor.constraint(equalTo: cg.trailingAnchor, constant: -8.0),
            hStack.bottomAnchor.constraint(equalTo: cg.bottomAnchor, constant: -8.0),

            hStack.widthAnchor.constraint(equalTo: fg.widthAnchor, constant: -16.0),

        ])

        let infoFont: UIFont = .italicSystemFont(ofSize: 10.0)
        let testFont: UIFont = .systemFont(ofSize: 12.0)

        var testStr: String = "This is some example text to test truncation consistency. At the end of this line, is a pair of newline chars:\n\nA HEADLINE\n\nThe headline was also followed by a pair of newline chars."

        for i in 3...10 {

            let infoLabel = UILabel()
            infoLabel.font = infoFont
            infoLabel.text = "UILabel - numLines: \(i)"
            labelStackView.addArrangedSubview(infoLabel)

            let v = UILabel()
            v.font = testFont
            v.numberOfLines = i
            v.text = testStr
            v.backgroundColor = .yellow
            v.lineBreakMode = .byTruncatingTail
            labelStackView.addArrangedSubview(v)

            labelStackView.setCustomSpacing(16.0, after: v)

        }

        for i in 3...10 {

            let infoLabel = UILabel()
            infoLabel.font = infoFont
            infoLabel.text = "TextViewLabel - numLines: \(i)"
            textViewStackView.addArrangedSubview(infoLabel)

            let v = TextViewLabel()
            v.font = testFont
            v.numberOfLines = i
            v.text = testStr
            v.backgroundColor = .cyan
            v.lineBreakMode = .byTruncatingTail
            textViewStackView.addArrangedSubview(v)

            textViewStackView.setCustomSpacing(16.0, after: v)

        }

        scrollView.backgroundColor = UIColor(white: 0.95, alpha: 1.0)

    }

}