If you catch that rear handle and kill the motors it's going to flop down pretty hard. Could damage the camera gimbal if it swings against your body.
Not sure the way it clips to the tail that it is strong enough during a catch. Is there something to make it so it cannot unclip?
Is the rear leg too long? It seems on landing the nose up attitude of the stock MP is not right. Not sure if this could confuse the IMU during start up.
I think you need to test the automatic landing after RTH following a 10m climb after takeoff. I suspect that rear widget may be in camera view.
How stiff is that plastic in hot weather? (I know nothing about 3D printing.).
Other than that I like the design, esp. the fore extensions. Sort of a "stinger" look to them.