How can i increase the number of ticks, a controller goes through, in a staggered animation (Flutter)

i created my staggered animation following the official tutorial : https://flutter.dev/docs/development/ui/animations/staggered-animations.

The issue is that the number of ticks the controller goes thought (and thus the frame rate) is low, about 50 fps (it can be even lower in some other exemples i tried). Is there a way to increase the number of ticks an (animation)Controller goes through, or is there a better solution for this ? Thanks !

Here's a gif of the laggy widget: https://i.stack.imgur.com/aXdef.gif ==> (StackOverflow does not want me to put images yet, so you got a link instead)

I printed each frame/tick, here's what i got:

flutter: 100.0 -> frame 0
flutter: 100.0 -> frame 1
flutter: 100.32715344429016 -> frame 2
flutter: 100.72060895198956 -> frame 3
...
flutter: 199.6830144248088 -> frame 40
flutter: 200.0 -> frame 41
flutter: 200.0 -> frame 42
flutter: 200.0 -> frame 43
flutter: 200.0 -> frame 44
flutter: 200.0 -> frame 45
flutter: 200.0 -> frame 46

Here is my full code:

class VerificationBox extends StatefulWidget {
  @override
  _VerificationBoxState createState() => _VerificationBoxState();
}

class _VerificationBoxState extends State<VerificationBox>
    with TickerProviderStateMixin {
  bool _isOpened = false;
  AnimationController _controller;

  @override
  void initState() {
    super.initState();
    _controller = AnimationController(
        duration: const Duration(milliseconds: 1000), vsync: this);
  }

  Future<void> _playAnimation() async {
    try {
      _isOpened
          ? await _controller.reverse().orCancel
          : await _controller.forward().orCancel;
    } on TickerCanceled {
      // the animation got canceled, probably because it was disposed of
    }
  }

  @override
  void dispose() {
    _controller.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return GestureDetector(
      onTap: () {
        _playAnimation();
        _isOpened = !_isOpened;
      },
      child: StaggerAnimation(controller: _controller.view),
    );
  }
}

class StaggerAnimation extends StatelessWidget {
  StaggerAnimation({Key key, this.controller}):
        opacity = Tween<double>(
          begin: 0.0,
          end: 1.0,
        ).animate(
          CurvedAnimation(
            parent: controller,
            curve: Interval(
              0.9,
              1,
              curve: Curves.linear,
            ),
          ),
        ),
        width = Tween<double>(
          begin: 100.0,
          end: 200.0,
        ).animate(
          CurvedAnimation(
            parent: controller,
            curve: Interval(
              0.0,
              0.9,
              curve: Curves.easeInOutCirc,
            ),
          ),
        ),
        super(key: key);

  final AnimationController controller;
  final Animation<double> opacity;
  final Animation<double> width;
  int counter = 0;

  Widget _buildAnimation(BuildContext context, Widget child) {
    print('${width.value} -> frame $counter');
    counter++;
    return Container(
            decoration: BoxDecoration(
              borderRadius: BorderRadius.circular(35),
              color: Colors.green,
            ),
            // curve: Curves.easeInOut,
            height: 25,
            width: width.value,
            // duration: Duration(milliseconds: 500),
            child: Row(
              children: [
                Container(
                  alignment: Alignment.center,
                  width: 80,
                  height: 50,
                  decoration: BoxDecoration(
                    borderRadius: BorderRadius.circular(35),
                    color: Colors.red[300],
                  ),
                  child: Text(
                    'verification',
                    style: TextStyle(fontSize: 13),
                    textAlign: TextAlign.center,
                  ),
                ),
                Expanded(
                  child: Opacity(
                    opacity: opacity.value,
                    child: Text(
                      'BCDEFG',
                      textAlign: TextAlign.center,
                    ),
                  ),
                )
              ],
            ));
  }

  @override
  Widget build(BuildContext context) {
    return AnimatedBuilder(
      builder: _buildAnimation,
      animation: controller,
    );
  }
}