Bhyve backup options?

Hello.

I wonder what kind of backup solution (from local host server running VMs
to a remote box) do you have, for your VMs?

I was playing with the zfs_autobackup script (
github.com/psy0rz/zfs_autobackup) and I feel like it's too complicated.

Now I plan to return to rsync over SSH. Is this a good idea, or any
alternative you might suggest?

Second -and much important- question:

Is it a bad practice to take a backup of a running bhyve VM instance
(actually doing tar on the 'disk1.img' VM disk)? Should the VMs be stopped
before doing so? Any data loss possibility, otherwise?

If powering them off is needed, and in case of dozens of VMs running, how
would you handle that?

Many thanks in advance.