>>2794313That is interesting.
Looking at my model, the cancellers serve as parents for both the IK and weighted D chains. Your issue must be caused by not parenting all three bones that affect the joint, including the 足変形 ones, to the cancellers. One other difference I could spot was that my D-bones lack forward links, but it doesn't seem to matter.
On another note, consider this sort of weighing pattern (with physics+bone alignment rigids) if you ever feel like flat asses and unusually deforming upper thighs aren't your thing. The bone parenting is not ideal, but that was the best option I had with a jiggly butt. The idea behind IKs is to keep the jiggle oriented toward a certain angle regardless of the relative angle between the legs and the torso, no matter which bone is causing it. I originally found this idea used in Alicia Solid Kai's shoulders (which allow you to anatomically lift breasts by rotating the shoulder, shoulderP, or arm bones while taking up only one BDEF4 weight slot), and I've also incorporated it in my wife's choker-harness link (to keep the ring that connects the choker to the harness roughly in the same position without clipping through the body, regardless of the rotation of the neck) and frontal slingshot straps (to prevent them from physically sagging too much).
The ass also clips through the pants, which is more of an issue and could be solved by matching the weights through a data transfer modifier, for example, or UV/vertex/material morphs, or even a bone morph if the clothing used separate weights.
