The complication is that a lot of RS users want the teaser applied to private posts because, for extra security, they set all their exclusive posts private and then let Role Scoper expose those "private" posts to the appopriate users. That way, if Role Scoper is accidentally deactivated or fails to initialize due to a conflict with some newly installed plugin, WordPress still defaults the posts to non-visible. I understand that you are using "private" as an additional distinction and would prefer for those posts to be completely hidden even when the "public but exclusive" posts have the teaser applied. For now, you can make that happen by modifying query_interceptor_rs.php as follows:
change
$list_private[$object_type] = true;
to
$list_private[$object_type] = false;
I need to think about how to add this as an option without confusing those who don't care to deal with it.