Lock down Plasma?

[The_Great_Sephiroth]

I am currently working on an all-in-one system which will be cloned to other identical systems and then delivered to a client who takes care of special needs adults at multiple locations. As such, I have had two requests which I am looking to fulfill. There will be two accounts on these systems. One will be for the consumers who are able to use a computer and one will be for the company employees. They would like the consumer account to only have access to the Firefox browser and nothing else. Ideally the browser will start upon login with a fresh tab at Google. The K menu should only allow them to (re)start Firefox and logout, reboot, or shutdown.

The other request may be trickier. We need the accounts locked so users, both consumers and employees, cannot screw the desktops up. Crap like somehow deleting the activity managers and task managers from the taskbar. If we cannot prevent that, I need a way to quickly revert them to their stock settings. My best guess at this point would be to use the BTRFS file-system to snapshot the home subvolume once the accounts are setup, and then roll back if the accounts get screwed up. The only concerns I have with this method would be losing documents and what if we roll back after Plasma 6 or some newer KDE is out?
_________________
Ever picture systemd as what runs "The Borg"?

[asturm]

I can't help you much there, the KDE forums would be a better place for this question. However, this link might be useful: https://userbase.kde.org/KDE_System_Administration/Kiosk/Introduction