Knock-Knee correction in body proportions (or tracker mechanics idk where it'd go realistically)

[InsaneGrox]

Some of us (myself included) have legs that bend inwards slightly, this can be either implemented as either a knee yaw offset, or a lower leg roll offset (preferrably latter in my case, for some former might be better.), or maybe even a foot yaw offset (some of us can pencil pose with our feet angled out, also as a toggle so in-game calibration can be correct)

[ButterscotchV]

There's some serious quirks with legs that we currently don't handle at all, it seems to affect people to various extents, but it would be very nice to investigate and have a proper report of the issue with data so we could solve this.