Question for pool configure with various disks q'ties within one pool.

Hi all.

When we initial installation of ZS3-2 with 2 logzilas and 20 disks, the pools are like that.
In case of raidz2.
     two vdev groups on pool-0.
     one vdev has 7d+2p+1sp

Let suppose that second addition disks (24 disks, same disk specs (rpm,size,type)
If we add these disks on exited pool-0.
there are two vdev groups added with different disks q'ty.
new added vdev has 9d+2p+1sp.

Finally, there are four vdevs on one pool-0.

     1st. vdev had 7d+2p+1sp (10ea)
     2nd. vdev had 7d+2p+1sp (10ea)
     3rd. vdev had 9d+2p+1sp (12ea)