The Open Suse Security team has released a long article about how they review Security issues with KDE6 , It's quite impressive.
I've found out of all the KDE6 Distros I've tried so far Open Suse tumbleweed to be the best for stability and Just working.KDE6 release: D-Bus and Polkit Galore
In the context of the KDE desktop version 6 major release we looked into a series of D-Bus services using Polkit for authentication. This led to a couple of interesting findings and insights.security.opensuse.org