State of ZFS xattr support in FreeBSD

I'm trying to work out whether or not, or rather to what extend, xattrs are supported in FreeBSD using ZFS. I've read some conflicting information. 1. zfs get xattr lists it as on (default) for /, /usr and /var, but as off (temporary) for all other datasets, including children of those mentioned above. 2. Running zfs set xattr=on zroot/usr/home I get the message > property 'xattr' not supported on FreeBSD: permission denied. 3. This agrees with [the zfs man page](https://www.freebsd.org/cgi/man.cgi?query=zfs&apropos=0&sektion=0&manpath=FreeBSD+10.2-RELEASE&arch=default&format=html) : > The xattr property is currently not supported on FreeBSD. 4. setextattr, getextattr and lsextattr seem to work well enough. 5. I also managed to save and restore a device file node using rsync --fake-super, and could see its data using lsextattr and getextattr. 6. Wikipedia has some discussion in the [xattr talk page](https://en.wikipedia.org/wiki/Talk:Extended_file_attributes#FreeBSD) . Apparently there once was a claim that ZFS supports xattr since FreeBSD 8, but that was removed later on, with reference to the manpage (see 3.). Currently I get the impression that extended attributes on zfs work in practice, but that the xattr property which would control their use does not work as it would in other zfs distributions. But I'd like to hear that confirmed (or corrected) before I trust large amounts of backup data to an rsync --fake-super running on such a machine. I'd rather not lose all my metadata due to known xattr problems. If it matters, this is a *very* fresh FreeBSD 10.2 install I just set up, with ZFS set up by the installer.