Custom AD Alias Login Option - Normalize Suffixes

I have a client attempting to use DUO for push notifications. They can login with UserPrincipal Name for the that specific application but for the other application they want to use a suffix to the principal name example User1 becomes SFUser1. When they do this they have to add alias of SFUser1 to the user for DUO to authenticate.

So my question is, does DUO have a way to drop the suffix (SF), instead of having to manually create alias for all of these users?

No, other than normalizing the username (dropping an @domain suffix or DOMAIN\ prefix from what is received as the username) we do not have a way to transform a username into a different format or value.

If the username they want for the other application exists in AD/AAD as an attribute value they can pull it in via directory sync by mapping that attribute to one of the user alias attributes in Duo.