I started making my lattice like deformations with stretch/null type deformer matrices. It was working for the skull, and I'll still preserve it (it's a system that uses IK and stretch with cross hatch node offset controls for lattive deformations and squash/stretch volume preservation), perfect - but it wasn't working well with the facial aspects like the rim around the eyes and mouth. It would take a long time to configure, and the built in constraints of Blender/Bforartists weren't giving me the results I wanted without a lot of hard work. It would a tonne of configuration, so I thought.. better do that on controllers, not deformers as planned - but instead, let's tie in the facial drawing controls into Spline IK's - which I already know how to export to UE with shadow rigs.
So I turned my plans upside down and will rebuild the facial setup.
Continued Plans:
Again, this doesn't mean the controls change much. I'll still have a primary general quick draw controls for general posing animation workflow then the detail controls for shape/correction animation workflow.
Steepshot