In attempting to create an optimised avatar, I used a Phys Bone script on the head bone, set Multichild type to ignore and added the jaw and eye bones to the ignore list.

On the avatar I have three bones in each ear, three in each wing and four in the tail, totalling 16. However, when the performance rating is calculated, I get a score of Medium and I'm told 22 bones are being phys transformed, even though the head, eyes and jaw are not being transformed. These should not be included in the performance rating.