try turning off the IK on both legs, also if you fix the shin bending problem you can save the 30 frames of the walkcycle you have fixed to the walkdesigner folder in poses then whenever you run walkdesigner you can choose your custom walkcycle...
i will have to do a test of the A3 and walk designer to see what i come up with..

Getting old and still making "art" without soiling myself, now that's success.