Autoenroll users based on User Principal Name (UPN)

Autoenroll users based on User Principal Name (UPN)

From what I can understand, it is not possible to auto enroll users based on User Principal Name (UPN - e.g  firstname.last@domain.com ) and they can only be enrolled based on sAMAccountName.
Can this be modified so that we can also enroll based on UPN?

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