List<Transform> listExtra = new List<Transform>();
Transform[] trans = generatedFbx.GetComponentsInChildren<Transform>();          //all transforms in Attachment
Transform[] bakedTrans = generatedObject.GetComponentsInChildren<Transform>();  //all transforms in Avatar prefab
foreach (var obj in selectExtraBone)
{
    if (!obj.Value)
        continue;

    for (int i = 0; i != trans.Length; ++i)
    {
        Transform tran = trans[i] as Transform;
        if (tran.name == obj.Key)
        {
            bindPose.Add(tran.localToWorldMatrix);
            //以下为修改后代码 (replacement)
            for (int j = 0; j < bakedTrans.Length; ++j)
            {
                if (bakedTrans[j].name == obj.Key)
                {
                    listExtra.Add(bakedTrans[j]);
                    break;
                }
            }
            //以下为原始代码 (origin source code)
            //listExtra.Add(bakedTrans[i]);
        }
    }
}