Yup, I think you’ve summarised this nicely, and there's not much to add. Thanks @Yoann Rodière !

We discussed this on Zulip: https://hibernate.zulipchat.com/#narrow/stream/132092-hibernate-search-dev/topic/Static.20metamodel.20HSEARCH-4951

Key takeaways:

1. Since the static metamodel may be referenced in the same Java project where it’s generated, we must generate it before, or during, compilation – otherwise compilation would fail.
   Thus, Maven/Gradle plugins are unlikely solutions: we need a javac annotation processor.

2. In the annotation processor, execution of application code is impossible.
   Thus, when application developers expect a static metamodel, we cannot support programmatic mapping, binders and things like PropertyMappingAnnotationProcessor as they are: we need new solutions to replace them.

3. In the annotation processor, CDI is unavailable.
   Thus, when users expect a static metamodel, we cannot support CDI instantiation of binders: application developers will need to rely on reflection-based instantiation for these components.

4. In the annotation processor, access to Hibernate ORM’s Metadata objects is impossible: https://hibernate.zulipchat.com/#narrow/stream/132094-hibernate-orm-dev/topic/Hibernate.20Models.20and.20Annotation.20Processors
   Thus, we need another way of inferring the Hibernate ORM metadata we need (there isn’t much).

I think that’s the gist of it – feel free to add anything I forgot @Marko Bekhta 🙂