How to handle active directory hybrid migrations?

For reference for myself when I check this later:
System user functions]

I can only think of two ways so far to handle an AD hybrid user migration of usernames and or contact info.

Option 1
Both old and new users exits in the AD hybrid till I update roles of the new users.

Option 2
I create a duplicate of the existing user source to use till I can put roles into the migrated AD hybrid user source.

Is there another option?