An idea after discussing reliable pagination strategies and the need for repeatable-read in some scenarios. Not reopening the index might be useful in other cases too, for example to provide repeatable-read within a Session when no changes have been flushed to the index, not least it will improve performance as it will avoid some IO hits to verify if the IndexReader is still up to date (or in worst case when it's not up to date that would even force a refresh).

So overall this could improve usability by better matching repeatable-read semantics within a Session, and improve performance by reducing the index reopening ratio.