Oliver,
Thanks for your patience. I was just looking at the code and may have found the culprit that's causing the behavior your seeing. Can you edit the /plugins/socialprofiles/communitybuilder/communitybuilder.php file. Around line 104, you'll see:
if ($cbField->published && $cbField->profile && $cbField->registration && !$hideField)
That line is what determines when a field is shown and requires that the field is published, profile and registration. Please try to update it like:
if ($cbField->published && $cbField->registration && !$hideField)
That will make it so the field is set for registration and published, but doesn't have to be set to profile view.
I'm not sure why we have that requirement. Please let us know how that goes for you and we'll investigate removing that requirement in a future release.
Thanks,
Alex