The Dev Figure is for Development of clothing or any conforming item.
It is not for development of hand , face or body poses.
it shouldn't be used as the target of an injection pose or as the figure you are using in your scene for Posing. There is no IK so you will definitely get some funkiness( as with your screenshots) in the ankles when trying to use this Dev figure for more then what it was intended.
I hope that helps.
JC