To prevent displaying query results that are very large, an option could be provided on the collection group to limit the number of displayed records. Note, the lookup framework currently has a feature to limit the number of query results. This would be a different option that can be applied to any general collection group.
Add a property of type int to CollectionGroup named displayCollectionSize. After the filters run on the collection, limit the size (if greater) to the configured displayCollectionSize. The default should be set to -1 to indicate no limit. Note the filter should be done before the layout managers run and should not impact the actual collection on the model (similar to how filters work).