For those of you who might be interested in what may be coming, the KDE Neon Developer Edition has changed the way updates are handled. Instead of a long list of packages in Discover, a consolidated "meta-package" is loaded, called System Updates. These updates are then authenticated by the user for offline processing, handled at the next reboot. The boot time messages aren't very refined (a lot of redundant info about processing the updates offline) but you can see what updates are being processed. Then, after the updates are finished the system reboots for normal operation.

I am not sure if these changes will migrate to the User Edition any time soon. Perhaps one of the developers can reply to this thread with clarifications, if needed.