Currently when a custom field has "Appear During Editing" set to no, in the backend it displays on the profile anyways.
I gave this some thought and have come to the conclusion that there isn't really any benefit to showing custom fields on profiles in the backend when their "Appear During Editing" is set to no. Take for example the Recaptcha, when I edit a profile on the backend I always have to use it to edit the profile. An admin should not have to use a Recaptcha when editing a profile.