Maybe so. The documentation seems to be all over the map, and the GUI suggests using "attended sysupgrade" for upgrades.

...which I tried doing, a week or so ago, for a minor point release update within the 25.12.x series. And then the router went out to lunch and didn't come back.

Getting it going again wasn't so bad as such things go. My router has a huge advantage here in that it's a Raspberry Pi 4, so it's easy to remove/replace/re-do the flash device and start over.

(Except: I get all out of sorts when I need to do Internet stuff to fix my Internet connection while that Internet connection is absent.)