Doc values are supposedly a more efficient way to look up a particular field value for a particular document. Maybe we should use that to retrieve document IDs when searching, instead of relying on the stored fields and indexSearch.doc( ... )?
See the comments on https://github.com/hibernate/hibernate-search/pull/2043/ (second review) in particular.
We'll need to check whether there is an actual performance improvement.
Note that stored fields are also useful when debugging using luke, so we may not want to disable field storage... ?