"Alternate address" and "Alternative contact" appear on /cgi-bin/koha/members/moremember.pl?borrowernumber=1 even when the fields used for them are hidden by BorrowerUnwantedField. If you try to click "Edit" or "Add", you'll be taken to an editor screen with no fields - just "Save" and "Cancel" buttons.
A quick hack workaround is just to hide those fields using CSS, but that's not really optimal.