The BorrowerUnwantedField syspref does not include password expiration date. It should be included in order to allow the use of password expiration dates without manual editing.
I thought only the superlibrarian was supposed to see and edit the password expiration date? See bug 29926 I'd love to make it more flexible, as usually only very few have superlibrarian permissions.
Oh! You're right! Thank you, I had my superlibrarian blinders on. I'm inclined to close this bug, then.