When you mirror the heal, foot and toe control, you select all keyframes, then:
"copy"->"paste" (on other foot)
But when you need to mirror the base, you do it keyframe by keyframe, and "copy"->"paste mirrored".
I tried just to select all keyframes for the base, and do "copy"->"paste mirrored". It seemed to work.
What's the reason for doing it keyframe by keyframe?
Hope the question maks sense.
Regards.