Resolved as part of the Search 6 proof of concept groundwork.

The APIs are now more "layered":

• the engine exposes generic APIs that should work for any mapped type, be it POJOs, JSON, etc, because these APIs are focused on the index (they deal with indexes and index fields, not classes and object properties). See for instance SearchQueryResultDefinitionContext.
• the mapper declares APIs that are closer to the mapped type. See for instance org.hibernate.search.v6poc.entity.pojo.mapping.PojoSearchManager#search(java.util.Collection<? extends java.lang.Class<? extends T>>)
• in the case of POJO-based mappers, the actual mapper implementations can refine the APIs defined by the "abstract" POJO mapper. See for instance the ORM integration, where we override org.hibernate.search.v6poc.entity.pojo.mapping.PojoSearchManager#search(java.util.Collection<? extends java.lang.Class<? extends T>> to org.hibernate.search.v6poc.entity.orm.mapping.HibernateOrmSearchManager#search(java.util.Collection<? extends java.lang.Class<? extends T>>)