Seems like using the Custom Shape Transform under the Bone > Viewport Display settings can keep the control bone in place without dependency cycles. For instance, setting the transform to the toe bone of that leg would visually move the control bone to the toes. Especially if the toes are mirroring the rotation of the control bone, it makes fairly intuitive visual sense.
It seems to work as expected with stretching enabled (I’m guessing, at least; stretching seems to do some wild stuff).
