dragThreshold of Flickable not taken into account with programmtically sent QMouseEvents

When dragging a Flickable it normally requires the user to cross the dragThreshold until the contents actually move. This works fine with a mouse or on a touchscreen, but if QMouseEvents are sent programmatically via QCoreApplication::sendEvent(window, event) then the contents are moved directly, without taking the threshold into account.

See the attachment for a reduced example of this behavior. Can be built and run via

cmake --preset debug && cmake --build --preset debug && ./build/debug/Test

Click on the "start" button to see the contents move a bit less than one red bar.  Trying to drag the distance of just one red bar is not possible here by using the mouse/touchscreen.