This component would set the position and rotation of the specified transform to the position and rotation of a the left or right VR controller, hand, or whatever is the IK target for that hand. If that hand is not tracked, the position isn't updated and if a parameter name is given, it's set to false.

This is different from parenting to the hand bone because it's not affected by the IK, allowing for animating the arms while still having access to the controller tracking data.

In my use case, the transforms with the controller constraints would be used to parent a gun to the dominant hand, animating that hand to look like it's gripping the grip and use the other hand as a look at constraint target for the gun and animate that hand to look like it's gripping the handguard. Currently this is only possible if you create fake bones for the arms used for tracking and another set for skinning the mesh