@Steven-Collins So I have my MicroSD getting mounted now. Turns out I'd not added all the fields, leaving off the last two. Oops, that doesn't work!

Is this from the Omega1 documentation at https://wiki.onion.io/Tutorials/Using-USB-Storage-as-Rootfs ?

No, it appears in the current Omega2 documentation (https://docs.onion.io/omega2-docs/extending-omega-memory.html#going-further-2).

I manually created an entry in /etc/fstab to mount my MicroSD, but it doesn't get mounted when I execute "mount -a". Started to look at docs to see how OpenWRT is different from every other *nix I've worked with in the last 30+ years. Still don't have an answer.

Seems strange that I'd have to add distfeeds to get something so basic working.