One of the signature engine of IPS 6.0 is Meta engine.
Meta-Defines events that occur in a related manner within a sliding time interval. This engine processes events rather than packets. As signature events are generated, the Meta engine inspects them to determine if they match any or several Meta definitions. The Meta engine generates a signature event after all requirements for the event are met.
All signature events are handed off to the Meta engine by SEAP. SEAP hands off the event after processing the minimum hits option. Summarization and event action are processed after the Meta engine has processed the component events.
But the large number of Meta signatures could adversely affect overall sensor performance. You can remove the actions as metacomponents are not to be edited.