It seems that envers combine create and update step, and the latter step override all mod column.

Yes, the combination is normal. From the ORM side we basically see a PostInsertEvent and a PostUpdateEvent get dispatched by ORM. From the point of view of Envers, the record has not yet been created, so we merge both the INSERT and the UPDATE DML statements into a single RevisionType.ADD (aka create) record.

That said, I'm curious about a slight variant in scenario where during the INSERT you have a collection element persisted; does the same outcome occur or is this only problematic when the collection is empty.