QGesture issues on top of OS X

I'm developing a web browser supporting gestures to learn Qt.

I have a class extending QGraphicsWebView to grab gesture and handle them properly. The original idea was to grab QPanGesture, QPinchGesture, and QSwipeGesture. Unfortunately, I could only see events of type QPinchGesture on OS X.

I thought the problem was OS X's window manager, which is actually grabbing some gesture itself (3-fingers panning, 4-fingers swiping, etc.). I disabled all of the gesture (note: the tracking speed for my trackpad is set to highest possible value).
This didn't solve anything, I could only see events of type QPinchGesture since the qDebug for QPanGesture and QSwipeGesture didn't get triggered.

I then started grabbing both QTapGesture and QTapAndHoldGesture and I was surprised to see that pretty much every gesture I do get's recognized as a tap and hold!

You can get the source code to reproduce the issue from this repository: https://github.com/filipposironi/nexo-browser/tree/pinchablewebview .

I run the same application on Linux/X11 (without any kind of window manager) and I cannot even pinch to zoom (the only thing that's working on OS X) since I don't see any gesture even though xinput test-xi2, evtest, and mtdev-test show that multi-touch events make it from the kernel to the userspace.