I have found out that "systemsettings" complains with:

kf.kirigami.platform: Failed to find a Kirigami platform plugin for
style ""

That's because it misses x11/kde-plasma/plasma-integration.

OK to import plasma-integration?

Information for inst:plasma-integration-6.0.5

Comment:
Plasma Platform Theme integration plugins

Required by:
debug-plasma-integration-6.0.5

Description:
Qt Platform Theme integration plugins for the Plasma workspaces

Maintainer: Rafael Sadowski <rsadowski@openbsd.org>

• plasma-integration-6.0.5.tar.gz (2K)