Option to use a 'dot' to separate parts of a username

Had used this module lots for D6 as it worked so well to help create Drupal users from CiviCRM contacts.
Our policy is usually to pull in the first and last, but since we prefer to have first.last name, we go through the effort of Concatenating those in the csv before importing.
Since the module has the option for the following
Username Space: Include spaces in usernames, e.g. 'John' + 'Smith' => 'John Smith'.

I wondered if it would be trivial and acceptable to have an option for
Username separated with dot: username fields will be separated with a '.'

May be able to provide a patch if it will be accepted.