Get one bone to follow another/parenting issue

[CodyBDrawin']

In this one smart bone action I have set up with a specific order for parenting, I'm trying to have the base/top of the lower leg bone follow the pin bone (both are highlighted/selected), but the caveat is that it needs to be targeting a bone at my character's ankle, so it can't target the pin bone. Is there a way to do this to where the top of the leg will track the pin bone while still staying targeted/anchored to the ankle? Alternatively, what I'm trying to describe (and do) is that I want the knee to track the pin bone when it moves back along the upper leg bone, while still targeting the ankle. How do I solve this?

[Lychee]

The target bone part of Moho is very buggy from my point of view.

I've lost count of the number of build ideas ruined by this tool, or I've had to find workarounds that have considerably complicated my builds.
There are plenty of settings that can disrupt the proper functioning of a targeted bone, and I think (and I've expressed this in the past)
that developers should reprogram the target bones so that they take priority over everything.

Worse, sometimes the build is good, but all it takes is one change in it that the program hasn't taken into account for the final result to be buggy.
To correct this I copy paste my bones and redefine my targets so that it works

I think that with all the experience I have gained from these problems I can help you, but for that I would need your file or just the problematic part of the file.