It would be extremely useful to be able to expose some internal properties of a vision template for use in whatever container may hold an instance of that property.
As a simplified example, a "states" template could be created that has a single label component with custom properties that are set via a customizer. Internal properties are then bound to the label's custom properties. If these internal properties could be exposed for bindings to other components when an instance of the template is used, this would essentially allow reuse of the customizer that exists on the label.
I could use template parameters as "outputs" with scripting, but that's very script-heavy when doing a script based on a property that is changing with an animation in the style customizer.