CAM has 2 sets of reports: flexible and easy. All summary reports belong to easy reports group and for most detailed reports they are explicitly marked as either flexible or easy. The Top N calls report is summary report and thus belongs to easy reports group.

Among other differences between these reports groups there are two biggest:
- flexible reports can be scheduled for autogeneration and easy can't
- flexible reports reflects changes made in users lookup table immediately while easy reports require data to be reparsed to apply changes made in lookup tables

As it follows from the listed above Top N report can't be scheduled for autogeneration.
We're working contstantly on adding 'flexible' clones of 'easy' reports and summary reports will be released in a near future release.