Discover *always* wants a system restart to apply changes, no matter how irrelevant to system operation they are.
Today I have been notified of a single update, Google Chrome, and Discover still wants to restart the system after applying it.
It is quite possible to detect what actions specific to the updates applied are required, either system or daemon (eg) restart (eg Cockpit), without simply applying a blanket action.
Linux/KDE Plasma: Linux 5.12.15-300.fc34.x86_64
(available in About System)
KDE Plasma Version: 5.22.3
KDE Frameworks Version: 5.83.0
Qt Version: 5.15.2
Can you outline how to do that from the data that we have from PackageKit?
*** This bug has been marked as a duplicate of bug 435574 ***
I have no idea. However, as mentioned previously, the server management program Cockpit *does* do this in the same environment.
It's open source so perhaps you can just see how they do it.