Good point, and you were right to ask: in v1.0 the contact point was not consistent. I measured it: the foot line sat anywhere between 72 % and 85 % of the frame height depending on character and direction.
Fixed today in v1.1 (free re-download): every frame of every character is now 192 x 192, the feet stand on row 165 (0.86 of the frame height) and the character is horizontally centred, in all 768 frames. One pivot, set once. The few pixels of bob inside a cycle are the step itself, not cropping. It is now stated on the page and in the README. Thanks for pushing on this.