Has anyone built a better access control report?

Summary:

The Access Control report available in system reports is great but sadly is borderline unusable in apps with a large user count (can't sort). Also can't be automated which is a downer.

Has anyone written a a better mechanism to extract effective access for a user out of the app via groovy rule? In theory it's possible by extracting access permissions, dimension details then using logic to perform the necessary hierarchy reads to determine effective access. Thanks