Extend Action Constraint Paths

The Action Constraint ignores custom pose bone properties. Custom properties, such as "mouth_lock" in the Rigify face rig, are an integral part of rigging and animation. The action constraint not being able to animate these properties seems like a limitation.

An obvious workaround would be to use a driver to work around this problem, but it's not always desirable to use drivers.

Please let me know if I am missing something.