my background is mostly in chow gar tong long, but have recently changed to HME Tai Ji when I met Sifu Nicholas Karram.
I understand your position but as has been stated before, the bouncing is a result of training "long" energy so as not to hurt the training partner. from my experience you could use this type of force to defend yourself without hurting your opponent(if you so choose).
That being said i can personally vouch for the power developed in this school. At the most recent seminar on the Gold Coast One of Sifu Mizners Senior instructors was correcting the technique of a new student and demonstrating on me.
One strike to the ribs only and he was being gentle, I was lifted by the sheer force of the strike and my ribs have still not recovered, almost 4 weeks later.
This is only my limited understanding but The expression of fa jin is determined by the mental intent, and if the persons life is threatened instead of sending the force through the body it can be focused inside the body to damage organs or break bones.
Please come and see for yourself, all are welcome.