It would be great if you could allow a user to be able to keep tabs on contacts even after they have changed contact owner to another user, in another team, without them being able to see the whole teams contacts. Just the ones previously owned/created by that person.
This will allow people who just source leads/contacts to be able to only view the leads they have brought to the table but over multiple teams and really keep an eye on how their leads are progressing and which sales reps are doing the best with their leads.