zfs snapshot -o user:prop does not work with delegation

[avg-I]

As root, set up a test dataset and delegations for it.
I will use group wheel in this example:

$ zfs create rpool/test
$ zfs allow -g wheel userprop rpool/test
$ zfs allow -g wheel snapshot rpool/test
zfs allow rpool/test
---- Permissions on rpool/test ---------------------------------------
Local+Descendent permissions:
        group wheel snapshot,userprop

Now, as a user in wheel:

$ id
uid=1001(avg) gid=0(wheel) groups=0(wheel),2(kmem),5(operator),20(staff)
$ zfs snapshot -o org.freebsd.avg:myprop=test rpool/test@test1
cannot create snapshots : permission denied

The same command works fine as root.
Also, zfs snapshot + zfs set work individually for a user in wheel.