Since RSAT allows you to chain test cases it would be good to make the test case parameter file to support security roles apart from users. As it currently stands, it is difficult to test a test suite with different roles, for example, the purchase requisition flow with an approval workflow, which requires two roles as a minimum, usually, the clerk who submits the requisition and a manager to approve it. With two users and a couple of roles it is manageable, but when using 50+ different roles in a system it becomes a constraint.