I’ve now been using /e/os long enough that there’s an OS update available, but I can’t find anything on how applying an update differs from a fresh install. Surely I don’t need to do a wipe of my phone for this?
(Thus is for a Pixel 4a 5G “bramble”.)
Do I just re-do to install process minus the format step?
Usually a few days after the release, the system OTA updater propose you the update, if you accept,
it download the .ZIP, reboot to recovery, apply the update, then reboot to system.
You can also do the same by yourself if you don’t want to wait
.
the “custom recovery” is already installed
right !
as you want to keep your apps and settings
Oh, wow; there is an updater in the Settings and it says there’s an update. It never posted a notification, so I hadn’t noticed it. I though I was going to have to go through the whole thing with ‘adb’ again. 
Thanks!
That was surprisingly painless; other than having to re-flash Magisk, the updater took care of everything.
Kudos, dev team.