ZFS COW and virtual subclients

We have two backup servers running Fedora and using btrfs. We would really like to migrate them to FreeBSD and ZFS but the bug with ZFS, virtual subclients and illegal characters in ZFS volumes has stopped us.

Is there any movement on that, or should we just resign ourseleves to the fact that virtual subclients will never sork with ZFS?

See for example ZFS COW file backups and Virtual sub client names - invalid character '[' in name