https://src.fedoraproject.org/rpms/openssh/blob/f22/f/openssh-6.7p1-sftp-force-permission.patch
The chances of BSD either upstreaming this patch OR providing a patch which behaves differently to this one seems to me to be quite low.
I'd like to register a vote here. Fedora and therefore RHEL have been
shipping this patch for 6 years now:
