Improve search results when changing the requester field

I'd like to know if we can get more information in the change requester view. We have a lot of customers with similar names. More information such as being able to search on or show date of birth in addition to email address (a custom field) would help us to select the correct customer.

It would also help to be able to use the external ID in the search for the change requester field to pick the correct customer.

Background: We have a lot of customers with similar names and placeholder/generic email addresses to fill the field (many do not have their own email and use other forms of communication (e.g. phone call) to reach us.