Scorecards at a requirement level would allow a further categorization of the priority of work within a feature and release - a way to define the 'stretch' or 'nice to have' elements of a feature. By allowing a separate scoring within a feature, it will assist in detailed release planning.
Our organization also measures the business value of a release overall by aggregating the scores of the work completed in a release - not only at the feature level, but for each requirement.