I think it would be too dangerous if the arms of the pilots were in the Q-Raus arms.
Arms tends to be destroyed/amputated easily. You know what i mean.
Also, it would be hard to click on buttons, and, the number of buttons would be really smaller.
While, in the main cockpit where there is more space, pilot has access to more "visual" fonctions.
For the legs I think it would be very unconfortable to put legs inside the backpack. Try to be in that position for more than 30 seconds, you'll get the idea. The back is completely folded. It's not a natural position. Also for the neck, pilot would have to bend her neck completely to have her head vertical. What do you think?