Why these 18 raw expressions no match GUI idx for them

[zero5zc]

When attempting to edit .dna files in Maya, I encountered an issue with mh4 (after comparing with mh2).
In mh4 version, these 18 expressions (obtained through calibrated.getRawControlName()) are added to the raw expressions.
However, there are no corresponding GUI indices in calibrated.getGUIToRawOutputIndices(), and the indices of these 18 expressions are not found in calibrated.getGUIToRawOutputIndices().
I'm interested in understanding how these 18 expressions are associated with controls and how they function.
I'm confused about this!! Can anyone provide insights into this?

[marijavik]

Hello,

The expressions in question are not part of RigLogic and are not driven by face GUI as you’ve already noticed. Those are driven by RBF setup with 3 neck joints: neck_01, neck_02 and head. Rotations of those joints are inputs for RBF nodes and those nodes drive 18 corrective expressions. Maybe this image can help me to explain it better: