optimization and bug fix - sensors shouldn't interrogate the model if not enabled, see https://github.com/phetsims/energy-forms-and-changes/issues/191
optimization and bug fix - sensors shouldn't interrogate the model if not enabled, see https://github.com/phetsims/energy-forms-and-changes/issues/191

phetsims/energy-forms-and-changes,phetsims/energy-forms-and-changes,phetsims/energy-forms-and-changes