It you've ever tried applying an old Pose to Miki, that Japanses woman available from Content Paradise, you have have noticed some odd things happening with her fingers and thumbs. The reason is that her hands are meshed and rigged with a zero position close to the normal relaxed position, fingers slightly curved. Limits are also set, so that when you want a straight finger you can't bend them back too far. There are dials to control finger bends as a whole, but it does mean that all those convenient hand poses come out looking very odd. It occurs to me that the offsets in the zero positions could be used in a Python script to adjust a hand-pose.