The database itself isn't subsite aware, so I doubt that could be done. Anyone who can add a page to the system can already execute any database query they want.
My belief is that most queries/reports used in the cron package will probably be written by a developer, but the new format would allow non-developers to view the cron, and run it when they want (assuming they have the correct privilege).
Once a report works, a designer could make it look nicer by adjusting the template which would not require admin approval.
The new package could also be mounted once and only an admin added, this would duplicate the current package behavior.
