In order to see the test coverage of an application, you have to include the ruleset that contains the Test Cases (ruleset with 'Use this ruleset to store test cases' option enabled) to the application rule. However, this is not a ruleset you'd might want to package. Currently (to my knowledge) it's not possible to explicitly exclude a ruleset from packaging.
I'd like to see a feature in the product rule to explicitly exclude/include ruleset which have the 'Use this ruleset to store test cases' option enabled. E.g. a checkbox which I can check to 'Exclude Test Case rulesets?'. This way I can keep my Test Case ruleset in the ruleset stack of my application, but exclude them during packaging.