kreadconfig5
Read KConfig entries for KDE Plasma.
TLDR
Read a key from the global configuration
$ kreadconfig5 --group [group_name] --key [key_name]
Read a key from a specific configuration file
$ kwriteconfig5 --file [path/to/file] --group [group_name] --key [key_name]
Check if systemd is used to start the Plasma session
$ kreadconfig5 --file [startkderc] --group [General] --key [systemdBoot]