Finally got it working.
The widget highlight for the triangles uses edges and a center point to indicate hover state and selected triangles. Selected and hover triangles are slightly smaller than the actual triangle so if one triangle in a group isn't selected it can be seen. The hover triangle is also slightly smaller than the selected triangle so they can both be seen on the same triangle. Solid highlighting isn't practical because the marker triangle only has one color, making it impossible to tell if a triangle is selected or in a hover state or both. Right now green is selected and yellow is hover for both the vertex and triangle selections. Both widgets write to the same script node. The name of the node and the vertex or triangle indices are passed to it in the Node string connector. The widget uses the trueSpace standard of ctrl to add to a selection and shift to remove from a selection.Next up is to clean up the code and make something from it.
