It has nothing to do with overlap or hang in my case. I am short 5' 4" so my seat it moved up more than most I would guess. Because of the height of the car as well as the seat being push forward I turn my left leg sooner than my right leg and kind of stretch my left leg to reach the ground (trying to avoid putting additional scratches on the sill until I put my sill plates on when it is warmer out). Reaching for the ground with my left leg I notice my left upper back leg touches the button slightly which in my case moves the seat if there is pressure on the top of the button. So it comes down to pretty much sliding out of the seat and rubbing my upper back thigh on the button.
Maybe the leather seats in the GT are constructed with softer bolsters. I've tried to actuate the seat switch with my thigh by using all kinds of contortions and I did finally manage by moving the seat all the way forward and sitting half on my butt while stretching my leg on the ground and leaning back into the car on my butt while simultaneously making a sliding motion with my thigh pressing inward against the control for the seat back angle. But it was quite awkward and only worked if I relaxed my thigh muscle so it would conform around the control lever and also the seat cushion bolster.
If I had this issue i would change the way I exited the vehicle so as to avoid rubbing against on the control switch for the seat back angle. Using your current method, I would be wary of wearing out the seat bolster by exiting in such a manner. If a physical handicap prevents exiting in any other way, I would look into removing the plastic cover of the seat back controller to give your thigh less purchase on the switch lever. Alternatively, you could affix a thigh bumper around the switch area so the switch is protected from the way you slide up against the side of the seat.
There is a solution for every problem but everyone is different so the solution will vary depending upon your particular needs.