Yeah, thats right. But keep in mind that the
zfs.clone_copy setting also applies to “normal” instance creation as well (from an image), and not just copies of one instance to another.
The normal creation of an instance on a ZFS pool is to “copy” the image volume to a new instance volume. Normally this uses
zfs.clone_copy=true which means it just takes a snapshot of the source image to use as the instance volume. With
zfs.clone_copy=false the full image volume is duplicated for the new instance volume. With
zfs.clone_copy=rebase a snapshot is taken (same as
zfs.clone_copy=true), but on subsequent copies of the instance to a new instance, the new instance volume is duplicated based on only the differences between the source instance and the source image.
zfs.clone_copy=rebase is only different to
zfs.clone_copy=true when copying instances to another instance. Whereas
zfs.clone_copy=false will affect normal instance creation too.