Two parts I suppose
1. In Demo, I'd like to use actual data from our dev environments while showing the ease of authoring / testing policies, but don't want to send that over the wire to the playground
2. In day-to-day usage, it'd be a really nice experience! I think a lot of comparisons can be made to the GraphQL playground: sure I can do all those things from a command line or Postman, but having a tool-aware experience available where you're working would speed things up greatly!