One example: If an extension adds an AnnotatedType (e.g. using BeforeBeanDiscovery.addAnnotatedType()) and does not provide an id a new one is calculated using org.jboss.weld.util.AnnotatedTypes.createTypeId() - the generated signature contains all type annotations and all members with annotations.
In WildFly org.jberet.creation.BatchCDIExtension (jsr352 integration) adds an AnnotatedType for BatchBeanProducer. As a result the generated id for this particular type has ~ 20 KB.
Note that AnnotatedTypeIdentifier.asString() is also used to generate id of some beans.