Mixed ashift?

I have what I think is a pretty normal setup.. a bunch of HDDs plus 2 SSDs
(one ZIL, one SLOG).

The HDDs are standard 512 byte sector drives.  The SSDs have 8k page sizes.

In Illumos I added the SSDs to sd.conf and created the zpool and it shows
the HDDs as ashift 9 and the SSDs as ashift 13, like normal:

# zdb -C | grep ashift
            ashift: 9
            ashift: 9
            ashift: 9
            ashift: 9
            ashift: 13

The question is, how to replicate this in FreeBSD?  The old "gnop" method
doesn't work anymore, and setting "vfs.zfs.min_auto_ashift=13" causes it to
use 13 for the HDDs, which seems like a waste.  Is this not supported?

Thanks!
-Dustin