HI @Hrishi
The bones have limited eye tracking accuracy, to work around this issue we have also provided 2D vertex driven eyes models
Eyes
There are two eye models provided. The first model consists of 304 vertices and tracks the vertices surrounding the eyes and eyebrows. The second model consists of 192 vertices and does not track eyebrows.
These models can be used for a more precise eyelid occlusion than the 3D vertices provide. The vertex colors aver been set in the eyes models and matched to the tracked feature points on the face.
You can find those reference models in the article you’ve linked and you can add them in the new studio from the Assets>Add Mesh menu.
You can also open the Beauty template in the new studio to see how this model is used