@FilmDaft My bad, the Leader Pose does not allow you to play animation or physics in the child meshes. For that, you would need to use the Copy Pose From Mesh node in the ABP. You can simply replace the Input Pose node with this one and it should work. Make sure to select Use Attached Parent and Copy Curves.
You would also need to remove the Head mesh from the Leader Pose in your Blueprint and parent the Head to the Body you want to copy the animation from. In your case, I believe you need to parent the Head to the SK_Petite_Female_Tank.
I’m not sure I understand what you said about the body and UE4 skeleton… The live link skeleton drives the body? It shouldn’t be an issue, as long as they’re compatible and can share the animations.
And about Control Rig, you should be able to use it on top of everything. Let me know if the Copy Pose From Mesh works and if you can use the Control Rig you created!