Flutter: How to listen/get characteristic of a Text widget?

So, I am trying to make a border/stroke effect for Text widget using Stack and Positioned.

class BorderedText extends StatelessWidget {
  BorderedText({
    super.key,
    required this.text,
    required this.textSize,
    this.borderTextSize,
    required this.textColor,
    required this.borderTextColor,
  }) {
    borderTextSize ??= getBorderTextSize(textSize);
  }
  final String text;
  final double textSize;
  double? borderTextSize;
  final Color textColor;
  final Color borderTextColor;

  double getBorderTextSize(double textSize) {
    return textSize * 1.1;
  }

  @override
  Widget build(BuildContext context) {
    return Stack(
      children: [
        Positioned(
          child: Text(
            text,
            style: TextStyle(
              color: borderTextColor,
              fontSize: borderTextSize,
            ),
          ),
        ),
        Positioned(
          top: (borderTextSize! - textSize) * 0.5,
          left: (borderTextSize! - textSize) * 0.2,
          child: Text(
            text,
            style: TextStyle(
              fontSize: textSize.toDouble(),
              color: textColor,
              letterSpacing: (borderTextSize! - textSize) * 0.45,
            ),
          ),
        ),
      ],
    );
  }
}

In some cases like textSize >= 70, the border text overflows. How do I listen to the overflow of that text widget and apply the same to the top text ?