If I select MORE than 2 disks during install as a mirror, continuing is greyed out. If I reduce it to 2 disks I can continue, so um, why is that? Why does it matter? If I select 3 or 4, then just create a 3 or 4 way mirror, no? Then cycle through as many drives as are in the zroot to put a boot block in place. It's a big pain to do after the fact, the mirror part is easy enough, but then I have to create the boot partition on the added disks. Every BSD or Illumos install on a zfs mirror I've ever done has just created an any way mirror.

I was requested to put a limitation in the past, but to your point, it does not make sense to limit that. Also, at the time I implemented that, my understanding of ZFS was limited.

Anyway, it was a big pain to expand the pool to an every way bootable 4 way mirror (which was my objective). Looking at it from a perspective of what it would take to reproduce the machine from scratch if I had to, it was honestly a better path for me to add a desktop to a stock FreeBSD 14 install, and was able to do the simple LXDE which is frankly more appropriate for me. It's small and simple, and at the end of the day, what makes a GUI useful for me is being able to have multiple terminals that I can cut and paste between, and a browser that I don't have to go to another machine to use. It's a home lab NAS and I really just wanted a more fun and functional console. I have way more CPU and RAM than I need for that (10/20 cores/threads and 128GB), so while a console GUI on a server is totally unnecessary, it makes you smile to see a graphical interface there and LXDE runs perfectly acceptably on a Raspberry Pi 2.

Oh and what I am building is actually a failover pair of zfs NASs. This is all kind of a learning curve for me, or maybe, more accurately, a memory curve, as I've been using System V and Linux machines for years and years, and haven't really done BSD boxes in forever. But at the end of the day, the fact that FreeBSD (and Ghost for that matter) use forums for their community, and Illumos uses mailing lists and LibraChat I see as kind of a self-destructive move for it's future, sadly. Also for dead simple clustering CARP just seems like an easy answer, which I am using on my pfSense firewalls and works well enough.