Hey Wayne,
When I'm trying to move the opposite foot constrained along the X axis, -1.2 /2, the location of the foot is way farther back then it should be.
I've been trying to figure out the issue to no avail.
is it at the correct point in the cycle?
Hopefully this makes sense but each foot is half a cycle different.
In the video I think I mirrored each pose exactly at the same time, then I shifted it by half a cycle, and then adjusted the keyframes,
You might be missing one of those steps.
I hope that helps you figure it out.
I duplicated all the keyframes on the left foot, selected all of them and moved them back -12, but it's still over-extended.
hm... I will try again.