Auto populate Requester field with current user and hold it

Perhaps the [Last Modified by] field is what you want?  The last person to edit the record?  is that what you want?

I'm not understanding where the data comes from for the initial population of the [Request Owner].  Is this the [Record Owner] , ie the user who created the record.

No, the Record Owner is the Administrator. Data in this table is imported and updated. Managers use the app to request changes by modifying or adding a record. Hence why I was going with last modified.   I have a QB Automation set up that captures the name in the Last modified field and copies it to the Requester field.   This does not work because the Last Modified does not reflect the current user until it's saved.  So, it ends up showing the administrator that imported as the requester.   I feel like there should be a simpler solution.

Do Managers make their updates on a form or do they also use Grid Edit.

If they only use a form, then you can have a form rule to capture the current user who last modified the record via forms.

However, this will not work for Grid Edit.

They use both for & grid edit to modify, larger majority grid edit

This is getting tough.  If users mass update by grid edit and also the IT dept mass updates by import, then how do we know if we should update the Requestor.

How about an Action which updates the Requestor field to be the [Last Modified by] if the Last Modified by is not equal to (what ever userid(s) the IT dept Admin uses) 

The manager triggers the request with a check box.