we used able to do something like this :

cfg.getEntityTuplizerFactory().registerDefaultTuplizerClass( EntityMode.POJO, MyEntityTuplizer.class );

and in the new metamodel api, there is no such place to do this yet, so i'm thinking the SessionFactoryBuilder might be a good place.

another option is making this EntityTuplizerFactory as a service.

and this brings an other problem: where SettingsFactory and Settings will eventually go