This is confusing for two reasons:
1. Since they are not applet-specific, the logical place for the user to try to find them is in the KCM, but they're not there.
2. If you have multiple plasma-pa applets (e.g. with a multi-monitor setup where each monitor has a panel with a system tray on it), their settings compete and it's not clear which applet wins.

We should move the settings to the KCM, like the Notifications applet does. It uses kconfig to store the settings data in an rc file rather than the applet config, and implements a global singleton to make this settings data available to all the Notifications applets and let them read the same settings together. To handle the use case of there not being any notifications applets present, the KCM displays an error message and disables the settings that affect the applet when opened with no applets present.

The plasma-pa applet could benefit from doing the same.