Best practice for configuration consultant user account in production

Summary

To fully configure OLC for deployment user account must be an active employee, what is the preferred approach for managing with external consultants?

Content

For many modules configs can be fully built under the Implementation User account.  OLC requires active employee association to be able to see Learning Admin, Manager and Employee screens.  In non-production environments we have observed that there are several areas that are associated specifically with the user creating them, often stamped with the name of the person creating the object. 

What's the preferred approach with creating and assigning user accounts for implementation partners to manage deployment configs, tasks and processes in Production?  Are you all setting up generic accounts that can be re-used by the company or are you configuring individual user accounts for each member of the Learning project team?  What happens if a person that implemented an object or process is offboarded?