Baking reach keys, whether by saving a motion clip with "Bake Constraint Key" enabled, or right-clicking on a motion clip and choosing "Bake Reach Key", has been broken since at least iClone 7.2x.

The simplest way to demonstrate the problem is as follows:

1. Load an avatar and choose Modify -> Edit Motion Layer.
2. Create a very simple animation that causes the avatar's hips to move (e.g., simply translate the hips on the z-axis on the last frame).
3. Right-click the resulting motion clip and choose "Bake Reach Key."
4. Note that the avatar's hips are offset down on the z-axis each time you perform step 3, ruining any animation that requires precision.