Rollbacks pretty much only work on LineageOS. I've seen this come up a lot in the last year as multiple F-Droid apps pushed out a bad update and people wanted a fix ASAP rather than in a couple weeks.
You can probably extract the apk of the old version on your other phone, btw.
Thanks. I took the nuclear option and uninstalled Nova completely before sideloading the previous version.
Luckily, Nova has a very good backup/restore option, so I made a backup right before uninstalling and was back up and running in short order. I of course unchecked the box to allow auto updates.
I'm hoping this buys me a little bit of time to explore other launcher options in detail.
You can probably extract the apk of the old version on your other phone, btw.
http://7thzero.com/blog/extract-an-apk-from-android-devices-...