Early Palm Design
The aim of the palm of the hand is to connect all the fingers together, offer a point to grasp against and rounds off the humanoid aspect of the design.
Below is a render of an early design, this design demonstraters finger placement and offers a cutout for the thumb to rotate while other fingers are locked. This design does not currently offer the yaw DoF present in earlier designs. However, these axis offer added complication and most importantly, use up space. With only a rotation hinge and a magnified scale, the space required for these fingers is already lacking even without yaw movement.