We decided that the contribution for the issue HSEARCH-499 is not supposed to merge strategies with conditional expressions. Meaning that we're going to create a single-item items group for any entities on which a given condition can be applied.
The Hibernate Search team discussed a bit the topic. Maybe it is possible to implement a finer solution.
See Zulip chat.
With this we want to explore any ideas to provide a finer solution to that.