I am currently working on the rig for a simple robotic character. This character has tube-like arms which bend and deform smoothly using the curve modifier. This works great, but I had to figure out a way to keep the robot's hands attached to the right point at the end of the arm and to stay perpendicular to the arm path. I wrote a python driver to accomplish this which yielded great results as seen here.
However, the problem is that as far as I can tell Blender only updates the coordinates of Bezier Curve Handles when in edit mode, which means as soon as I attempt to animate the limb using shape-keys the hand is frozen at the last edit mode point regardless of driver dependency updates.. You can see the value I am using for the driver not changing during animation here.
So my question is essentially, where can I get the animated spline data used for object mode? If this is impossible, what are my options.