Drive Metahuman ControlRig at runtime

I have set up a project where every frame I get new values for ControlRig controls.
I want to use those values to drive the Face_ControlBoard_CtrlRig.

I tried adding a ControlRig Component to the Metahuman blueprint (BP_Ada in my case), set its calss to Face_ControlBoard_CtrlRig and then call the appropriate SetControl functions.
The controls are being set correctly, as far as I can tell, but they have no effect on the animation.

Also tried changing the Animation blueprint of the FaceMesh to a very simple one that just uses the ControlRig node.

Any ideas?

Some more information on this issue.
It looks like the “Control Rig” Animation Blueprint node creates its own instance of ControlRig which it does not expose.
I thought I’d create my own ControRig node, which inherits from AnimNode_ControlRig and set the ControlRig property to the ControlRig of the ControlRigComponent I had created but the property is private.