I've worked on a workflow that can translate data coming from face performance capture through iPhone and LiveLink app to 2D animations in Blender Grease Pencil.
It's not the usual mesh deformation through blendshapes: there is no 3D involved, apart from the head rotation. Mouth and eyes animation are frame by frame drawings linked to mouth and eyes open range read by the phone camera.
This is just a first quick setup with eyes and mouth open/close, eyebrows up/down, mouth side to side and a mouth pucker drawing.