With KDE4 you can use /etc/kde4rc to add an extra set of settings to use, e.g. put

Code: Select all

[Directories-default]
prefixes=/usr/share/company-x/kde4-profile/default/

in it to look at company-x settings first.

What's the plasma5 equivalent of this file? I've tried some obvious candidates (kderc, kde5rc, kf5rc) but they're not it.

Sorry for the late answer. Just saw this thread now.
As Plasma 5 uses xdg dirs you can just add a new folder (a.k.a. the one in prefixes or your example) to XDG_CONFIG_DIRS and XDG_DATA_DIRS variables.
See for example: https://github.com/ds9-common/default-s ... ttings-xdg

How would you do this but forcefully, meaning the end user cant change the settings?

Admin Documentations shows to add [$i] to enforce rules in the config files, but im assuming this wont work since the users XDG Conf Home will be read first.